[Android] App crashes when start from background

[brzezinol]

Description

I have created new app after update to VS 2022 17.1.0 Preview 2.0. Clean app crashes when is started from background with error: System.NotImplementedException: 'Either set MainPage or override CreateWindow.'

Steps to Reproduce

1. start app
2. tap backbutton for exit app
3. tap on app icon for start app
4. app craches with error System.NotImplementedException: 'Either set MainPage or override CreateWindow.'

Version with bug

Preview 11

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

Android 11

Did you find any workaround?

No response

Relevant log output

> am start -a "android.intent.action.MAIN" -c "android.intent.category.LAUNCHER" -n "com.companyname.checknewtemplate/crc64d27ca43a711fc7df.MainActivity"
> Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.companyname.checknewtemplate/crc64d27ca43a711fc7df.MainActivity }
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/CheckNewTemplate.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Mono.Android.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Java.Interop.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Collections.dll [External]
Resolved pending breakpoint for 'Android.Runtime.JNIEnv.RegisterJniNatives(System.IntPtr, System.Int32, System.IntPtr, System.IntPtr, System.Int32)' to /Users/builder/azdo/_work/1/s/xamarin-android/src/Mono.Android/Android.Runtime/JNIEnv.cs:124 [0x00000].
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Threading.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.InteropServices.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Threading.Thread.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Diagnostics.StackTrace.dll [External]
Loaded assembly: data-0x70d60808d030 [External]
Loaded assembly: data-0x70d60809d040 [External]
Loaded assembly: data-0x70d69c28c040 [External]
Loaded assembly: data-0x70d6080cd070 [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/netstandard.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Linq.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Collections.Concurrent.dll [External]
Resolved pending breakpoint for 'Xamarin.HotReload.HotReloadAgent.BreakpointSendToIde(System.String)' to D:\a\_work\1\s\HotReload\Source\Xamarin.HotReload.Agent\HotReloadAgent.cs:410 [0x00000].
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Text.Json.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Text.Encodings.Web.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.ComponentModel.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.Controls.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.ObjectModel.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.Graphics.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.Abstractions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.Loader.dll [External]
Resolved pending breakpoint for 'Xamarin.HotReload.HotReloadAgent.BreakpointCheckpoint()' to D:\a\_work\1\s\HotReload\Source\Xamarin.HotReload.Agent\HotReloadAgent.cs:405 [0x00000].
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Reflection.Emit.Lightweight.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Reflection.Emit.ILGeneration.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Reflection.Primitives.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.Essentials.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Core.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Hosting.Abstractions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.DependencyInjection.Abstractions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.Controls.Compatibility.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Hosting.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Configuration.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Configuration.Abstractions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.FileProviders.Physical.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.FileProviders.Abstractions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Primitives.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.DependencyInjection.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Configuration.FileExtensions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Options.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.EventLog.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.Configuration.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.Debug.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.Console.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Logging.EventSource.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Options.ConfigurationExtensions.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.RecyclerView.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.DrawerLayout.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.CustomView.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.Google.Android.Material.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.AppCompat.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.SwipeRefreshLayout.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.ViewPager2.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.ComponentModel.TypeConverter.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Private.Uri.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Diagnostics.DiagnosticSource.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Diagnostics.Tracing.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Extensions.Configuration.Binder.dll [External]
[hecknewtemplat] Late-enabling -Xcheck:jni
[hecknewtemplat] Unquickening 12 vdex files!
[hecknewtemplat] Unexpected CPU variant for X86 using defaults: x86_64
[NetworkSecurityConfig] No Network Security Config specified, using platform default
[NetworkSecurityConfig] No Network Security Config specified, using platform default
[debug-app-helper] Checking if libmonodroid was unpacked to /data/app/~~jMP0uwFGBytzwVkpuucVhg==/com.companyname.checknewtemplate-m803XLLW9rDErxU3KsgLkw==/lib/x86_64/libmonodroid.so
[debug-app-helper] Native libs extracted to /data/app/~~jMP0uwFGBytzwVkpuucVhg==/com.companyname.checknewtemplate-m803XLLW9rDErxU3KsgLkw==/lib/x86_64, assuming application/android:extractNativeLibs == true
[debug-app-helper] Setting up for DSO lookup in app data directories
[debug-app-helper] Added filesystem DSO lookup location: /data/app/~~jMP0uwFGBytzwVkpuucVhg==/com.companyname.checknewtemplate-m803XLLW9rDErxU3KsgLkw==/lib/x86_64
[debug-app-helper] Using runtime path: /data/app/~~jMP0uwFGBytzwVkpuucVhg==/com.companyname.checknewtemplate-m803XLLW9rDErxU3KsgLkw==/lib/x86_64
[debug-app-helper] checking directory: `/data/user/0/com.companyname.checknewtemplate/files/.__override__/lib`
[debug-app-helper] directory does not exist: `/data/user/0/com.companyname.checknewtemplate/files/.__override__/lib`
[debug-app-helper] Checking whether Mono runtime exists at: /data/user/0/com.companyname.checknewtemplate/files/.__override__/libmonosgen-2.0.so
[debug-app-helper] Checking whether Mono runtime exists at: /data/app/~~jMP0uwFGBytzwVkpuucVhg==/com.companyname.checknewtemplate-m803XLLW9rDErxU3KsgLkw==/lib/x86_64/libmonosgen-2.0.so
[debug-app-helper] Mono runtime found at: /data/app/~~jMP0uwFGBytzwVkpuucVhg==/com.companyname.checknewtemplate-m803XLLW9rDErxU3KsgLkw==/lib/x86_64/libmonosgen-2.0.so
[hecknewtemplat] Attempt to remove non-JNI local reference, dumping thread
[DOTNET] JNI_OnLoad: JNI_OnLoad in pal_jni.c
[monodroid] Creating public update directory: `/data/user/0/com.companyname.checknewtemplate/files/.__override__`
[hecknewtemplat] Attempt to remove non-JNI local reference, dumping thread
[monodroid-debug] Trying to initialize the debugger with options: --debugger-agent=transport=dt_socket,loglevel=0,address=10.0.2.2:57525,embedding=1
[monodroid-assembly] open_from_bundles: failed to load assembly CheckNewTemplate.dll
[monodroid-gc] GREF GC Threshold: 46080
[monodroid-assembly] open_from_bundles: failed to load assembly Mono.Android.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Java.Interop.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Collections.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Threading.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.InteropServices.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Threading.Thread.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Diagnostics.StackTrace.dll
[hecknewtemplat] Attempt to remove non-JNI local reference, dumping thread
[monodroid-assembly] open_from_bundles: failed to load assembly netstandard.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Linq.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.VisualStudio.DesignTools.TapContract.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.VisualStudio.DesignTools.TapContract.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.HotReload.Contracts.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.HotReload.Contracts.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Collections.Concurrent.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Text.Json.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Text.Encodings.Web.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.ComponentModel.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.Controls.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.HotReload.Contracts.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.HotReload.Contracts.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.VisualStudio.DesignTools.TapContract.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.VisualStudio.DesignTools.TapContract.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.ObjectModel.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.Graphics.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.Abstractions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.Loader.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Reflection.Emit.Lightweight.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Reflection.Emit.ILGeneration.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Reflection.Primitives.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.Essentials.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Core.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Hosting.Abstractions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.DependencyInjection.Abstractions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.Controls.Compatibility.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Hosting.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Configuration.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Configuration.Abstractions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.FileProviders.Physical.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.FileProviders.Abstractions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Primitives.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.DependencyInjection.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Configuration.FileExtensions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Options.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.EventLog.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.Configuration.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.Debug.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.Console.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Logging.EventSource.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Options.ConfigurationExtensions.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.RecyclerView.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.DrawerLayout.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.CustomView.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.Google.Android.Material.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.AppCompat.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.SwipeRefreshLayout.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.ViewPager2.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.ComponentModel.TypeConverter.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Private.Uri.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Diagnostics.DiagnosticSource.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Diagnostics.Tracing.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Extensions.Configuration.Binder.dll
[0:] Microsoft.Maui.Dispatching.Dispatcher: Warning: Replaced an existing DispatcherProvider with one from the service provider.
[monodroid-assembly] open_from_bundles: failed to load assembly System.Linq.Expressions.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Linq.Expressions.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.Controls.Xaml.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.Controls.Xaml.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly System.Xml.ReaderWriter.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Private.Xml.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Xml.ReaderWriter.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Private.Xml.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly System.Text.Encoding.Extensions.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Text.Encoding.Extensions.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly System.Memory.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Memory.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly System.Text.RegularExpressions.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Text.RegularExpressions.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.CompilerServices.Unsafe.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.CompilerServices.Unsafe.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly System.Numerics.Vectors.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Numerics.Vectors.dll [External]
Thread started:  #2
Thread started:  #3
Thread started:  #4
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.Serialization.Json.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Private.DataContractSerialization.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.Serialization.Xml.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.Serialization.Json.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Private.DataContractSerialization.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.Serialization.Xml.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly pl-PL/System.Private.CoreLib.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly pl-PL/System.Private.CoreLib.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly pl/System.Private.CoreLib.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly pl/System.Private.CoreLib.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.Serialization.Primitives.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.Serialization.Primitives.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly pl-PL/System.Private.DataContractSerialization.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly pl-PL/System.Private.DataContractSerialization.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly pl/System.Private.DataContractSerialization.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly pl/System.Private.DataContractSerialization.resources.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.CardView.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Microsoft.Maui.Controls.Compatibility.Android.FormsViewGroup.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.ViewPager.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Fragment.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Activity.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Lifecycle.ViewModel.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Lifecycle.Common.dll
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.SavedState.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.CardView.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Microsoft.Maui.Controls.Compatibility.Android.FormsViewGroup.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.ViewPager.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Fragment.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Activity.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Lifecycle.ViewModel.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Lifecycle.Common.dll [External]
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.SavedState.dll [External]
[libEGL] loaded /vendor/lib64/egl/libEGL_emulation.so
[libEGL] loaded /vendor/lib64/egl/libGLESv1_CM_emulation.so
[libEGL] loaded /vendor/lib64/egl/libGLESv2_emulation.so
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Loader.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Loader.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.CoordinatorLayout.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.CoordinatorLayout.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.Android.Glide.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.Android.Glide.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly Xamarin.AndroidX.Lifecycle.LiveData.Core.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/Xamarin.AndroidX.Lifecycle.LiveData.Core.dll [External]
[hecknewtemplat] Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
[hecknewtemplat] Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
Thread started: .NET Timers #5
[HostConnection] HostConnection::get() New Host Connection established 0x70d49806d850, tid 8838
[HostConnection] HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_EGL_image_external_essl3 GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_3_0 
[OpenGLRenderer] Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
[EGL_emulation] eglCreateContext: 0x70d488094b90: maj 3 min 0 rcv 3
[EGL_emulation] eglMakeCurrent: 0x70d488094b90: ver 3 0 (tinfo 0x70d4286fd950) (first time)
[Gralloc4] mapper 4.x is not supported
[HostConnection] createUnique: call
[HostConnection] HostConnection::get() New Host Connection established 0x70d498065c90, tid 8838
[goldfish-address-space] allocate: Ask for block of size 0x100
[goldfish-address-space] allocate: ioctl allocate returned offset 0x3f7ffe000 size 0x2000
[HostConnection] HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_host_composition_v1 ANDROID_EMU_host_composition_v2 ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_EGL_image_external_essl3 GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_3_0 
Thread started: <Thread Pool> #6
Thread started: .NET ThreadPool Gate #7
Thread started: <Thread Pool> #8
[monodroid-assembly] open_from_bundles: failed to load assembly System.Runtime.Intrinsics.dll
Loaded assembly: /data/data/com.companyname.checknewtemplate/files/.__override__/System.Runtime.Intrinsics.dll [External]
**System.NotImplementedException:** 'Either set MainPage or override CreateWindow.'

[zhouwangyang]

not repro on the latest build, please try on the latest build and tell us if any problems.

[brzezinol]

@zhouwangyang what exactly build version?

[zhouwangyang]

@brzezinol I reproduced on vs latest build 17.2.0 Preview 2.0.

[vamsitp]

FWIW...

// App.xaml.cs
protected override Window CreateWindow(IActivationState activationState)
{
    // Workaround for: 'Either set MainPage or override CreateWindow.'??
    if (this.MainPage == null)
    {
        this.MainPage = new MainPage();
    }

    return base.CreateWindow(activationState);
}

[shimingsg]

Not reproducible with android 11. app can be start.

[julienGrd]

@shimingsg can you explain why you consider this issue closed ? for me there is still a problem (im on android 11, maui-check say everything is up to date). The workaround of @vamsitp in not enough because we have to recreate all the MainPage so we lost the state the app when she was putted in background.

thanks !

[shimingsg]

@julienGrd I repro this by the repro steps on Android 11 with vs 32214.398.main, app can be start, not crashes, so I close it, if you can repro this issue, can you upload your repro project, or provide some repro video? it is helpful, thanks.

[julienGrd]

@shimingsg is it the same behavior than us ?

• first launch OK
• then put the app in background with back button
• then put back the app in first plan (with the button to show all opened app) => at this moment the app crash

I reproduce this with the starter project on my side so no need to upload one specific

[julienGrd]

actually i just made update to visual studio 17.2.0 preview 1.0, with fresh install of .net maui workload preview 13, and i still encounter the problem on a fresh startup project.

[rachelkang]

I can confirm this is still an issue, and am working on it! Thanks for the patience everyone. In the meantime, I can also confirm that @vamsitp's workaround is valid

[southsideringo]

zhouwangyang same here. Is there a temporary workaround? I mean the main page is already set to AppShell.xaml.cs. And wth happens when you override the launch? I'm guessing nothing good.

[jayveedee]

I haven't updated to the RC Maui version yet (still on Version 17.2.0 Preview 2.1) but the error did still persist on that version

[BinaryAssault]

I was able to verify I no longer have this issue (with the workaround removed) using RC1. I used the steps in OP to verify.