Exception window on launch and then non-functional

I'm on Windows 10. I tried both the installed version and the portable version just in case.

I get a Windows exception alert window as soon as I try to launch WAT.exe and the app remains non-functional even if I choose "Continue". The exception reappears every few minutes if I leave the WAT app open.

Based on a cursory peak at the stack trace, it seems like it might just be an issue with parsing the JSON response from a Warframe worldstate API. The behavior of the exception reappearing every few minutes would align with that (reappearing due to the app re-requesting the world state).

wat-exception

See the end of this message for details on invoking 
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
   at System.ThrowHelper.ThrowKeyNotFoundException()
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at ScriptFUSION.WarframeAlertTracker.Warframe.Fissure.ParseJson(JToken token)
   at ScriptFUSION.WarframeAlertTracker.Warframe.WorldState.<>c.<.ctor>b__8_0(JToken t)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at ScriptFUSION.WarframeAlertTracker.Warframe.WorldState..ctor(JObject json)
   at ScriptFUSION.WarframeAlertTracker.Warframe.WorldStateDownloader.<Download>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at ScriptFUSION.WarframeAlertTracker.Warframe.CurrentWorldState.<Download>d__27.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()

************** Loaded Assemblies **************
mscorlib
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4075.0 built by: NET48REL1LAST
    CodeBase: file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/mscorlib.dll
----------------------------------------
WAT
    Assembly Version: 1.0.1.0
    Win32 Version: 1.0.1.0
    CodeBase: file:///C:/Program%20Files%20(x86)/ScriptFUSION/Warframe%20Alert%20Tracker/WAT.exe
----------------------------------------
System.Windows.Forms
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4042.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4001.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
Newtonsoft.Json
    Assembly Version: 11.0.0.0
    Win32 Version: 11.0.2.21924
    CodeBase: file:///C:/Program%20Files%20(x86)/ScriptFUSION/Warframe%20Alert%20Tracker/Newtonsoft.Json.DLL
----------------------------------------
System.Core
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4075.0 built by: NET48REL1LAST
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Configuration
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
System.Numerics
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.3752.0 built by: NET48REL1
    CodeBase: file:///C:/Windows/Microsoft.Net/assembly/GAC_MSIL/System.Numerics/v4.0_4.0.0.0__b77a5c561934e089/System.Numerics.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

ScriptFUSION / WAT

Exception window on launch and then non-functional #2