System.InvalidOperationException: 'Sequence contains more than one matching element'

[DiegoVenancioVieira]

In blazor-server

System.InvalidOperationException HResult=0x80131509 Message=Sequence contains more than one matching element Source=System.Linq StackTrace: at System.Linq.ThrowHelper.ThrowMoreThanOneMatchException() at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable1 source, Func2 predicate) at RazorComponentsPreview.RuntimeComponentsGenerator.ReadAllFiles(List`1 razorFiles) at RazorComponentsPreview.RuntimeComponentsGenerator..ctor(IServiceCollection serviceCollection) at RazorComponentsPreview.RazorRuntimeCompilationExtensions.UseRazorComponentsRuntimeCompilation(IApplicationBuilder app) at BServer....Startup.Configure(IApplicationBuilder app, IWebHostEnvironment env) in C:\Users......\Startup.cs:line 109 at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at Microsoft.AspNetCore.Hosting.ConfigureBuilder.Invoke(Object instance, IApplicationBuilder builder) at Microsoft.AspNetCore.Hosting.ConfigureBuilder.<>cDisplayClass4_0.b0(IApplicationBuilder builder) at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.<>cDisplayClass13_0.b2(IApplicationBuilder app) at Microsoft.AspNetCore.Mvc.Filters.MiddlewareFilterBuilderStartupFilter.<>cDisplayClass0_0.gMiddlewareFilterBuilder|0(IApplicationBuilder builder) at Microsoft.AspNetCore.Server.IIS.Core.IISServerSetupFilter.<>cDisplayClass2_0.b0(IApplicationBuilder app) at Microsoft.AspNetCore.HostFilteringStartupFilter.<>c__DisplayClass0_0.b0(IApplicationBuilder app) at Microsoft.AspNetCore.Hosting.GenericWebHostService.d31.MoveNext()

[Levvy055]

Having the same problem using Net5 Blazor Server.