UWP - Object reference not set to an instance of an object - xamarin

Question

After upgrading Microsoft.NETCore.UniversalWindowsPlatform I cannot compile my Xamarin app-project in Release anymore, as I get an Internal compiler error: Object reference not set to an instance of an object.
I am using these NuGet packages
Acr.UserDialogs 5.2.2
ExifLib.PCL 1.0.1 (in portable project)
Microsoft.NETCore.UniversalWindowsPlatform 5.2.0
MR.Gestures 1.3.4
Newtonsoft.Json 7.0.1 (in portable project)
Splat 1.6.2 (in portable project)
SQLite.Net.Core-PCL 3.1.1
SQLite.Net-PCL 3.1.1
Win2D.uwp 1.18.0 (in portable project)
Xam.Plugins.Settings 2.1.0
Xamarin.Forms 2.3.0.107
Xamarin.Insights 1.12.3
XLabs.Core 2.2.0-pre02
XLabs.Forms 2.2.0-pre02
XLabs.IoC 2.2.0-pre02
XLabs.Platform 2.2.0-pre02
XLabs.Serialization 2.2.0-pre02
A log can be found here.
I hope anybody in here can help me.
All platforms are set to Compile with .NET Native tool chain.
UPDATE
If I build XLabs myself and set Compile with .NET Native tool chain to unchecked. These errors occurs.
App manifest
Error Found: The app manifest test detected the following errors:
<project> takes a dependency on Microsoft .Net Native Runtime Package 1.x framework but is missing the framework dependency declaration in the manifest.
Binary analyzer
Error Found: The binary analyzer test detected the following errors:
File C:\Program Files\WindowsApps\<project>_1.8.0.0_x64__r1myykanma94r\clrjit.dll has failed the AppContainerCheck check.
Supported APIs
Error Found: The supported APIs test detected the following errors:
API SystemFunction036 in advapi32.dll is not supported for this application type. clrjit.dll calls this API.
API DebugBreak in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API HeapValidate in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API LoadLibraryExW in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API RtlCaptureContext in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API RtlVirtualUnwind in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API TlsAlloc in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API TlsFree in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API TlsGetValue in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API TlsSetValue in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API UnhandledExceptionFilter in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API VirtualAlloc in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API VirtualProtect in kernel32.dll is not supported for this application type. clrjit.dll calls this API.
API ExecuteAssembly in uwphost.dll is not supported for this application type. <project>.exe calls this API.
API DllGetActivationFactory in uwphost.dll is not supported for this application type. <project>.UWP.exe has an export that forwards to this API.
UPDATE 2
I could easily rewrite the code, so I did not use Win2D.uwp anymore. Somehow I have installed Microsoft.NETCore.UniversalWindowsPlatform v 5.2.0 last friday, but the latest in NuGet is now v 5.1.0.
So now I am down to these NuGet packages
Acr.UserDialogs 5.3.0
ExifLib.PCL 1.0.1 (in portable project)
Microsoft.NETCore.UniversalWindowsPlatform 5.1.0
MR.Gestures 1.3.4
Newtonsoft.Json 7.0.1 (in portable project)
Splat 1.6.2 (in portable project)
SQLite.Net.Core-PCL 3.1.1
SQLite.Net-PCL 3.1.1
Xam.Plugins.Settings 2.1.0
Xamarin.Forms 2.3.0.107
Xamarin.Insights 1.12.3
XLabs.Core 2.2.0-pre02
XLabs.Forms 2.2.0-pre02
XLabs.IoC 2.2.0-pre02
XLabs.Platform 2.2.0-pre02
XLabs.Serialization 2.2.0-pre02
And this error occurs The assembly Windows in file C:\Program Files\WindowsApps\<app-name>_1.8.0.0_x64__r1myykanma94r\Windows.winmd has a non-empty exported type reference table. Every Windows Runtime assembly must have an empty exported type reference table.
UPDATE 3
I figured out uninstalling Win2D.uwp and compiling XLabs myself was the way to go.

Answer 1

I had that problem and the resolution was simple: I had a reference to the PCL version Newtonsoft.Json.dll both in my PCLs and in my UWP project. Older portable version (Portable40).
After I updated to the latest version of Newtonsoft.Json.dll (NuGet version 9.0.1) the compilation exception went away.
Keep in mind that when updating I replaced all references to the Newtonsoft libreary i.e.
In my PCLs I now reference the portable version lib\portable-net40+sl5+wp80+win8+wpa81
In my startup project I now reference the Newtonsoft package (my project.json file contents):
{
"dependencies": {
"Microsoft.NETCore.UniversalWindowsPlatform": "5.2.2",
"Newtonsoft.Json": "9.0.1",
"Xamarin.Forms": "2.3.2.127"
},
"frameworks": {
"uap10.0": {}
},
"runtimes": {
"win10-arm": {},
"win10-arm-aot": {},
"win10-x86": {},
"win10-x86-aot": {},
"win10-x64": {},
"win10-x64-aot": {}
}
}
which effectively uses the reference to C:\Users\<username>\.nuget\packages\newtonsoft.json\9.0.1\lib\portable-net45+wp80+win8+wpa81.
Published my solution at Xamarin forums quite a while ago and some people say this worked for them as well.