Could not load file or assembly 'System.Private.CoreLib…'

Question

I have a Xamarin.Forms app which targets .net standard 1.4. On the UWP app which has minimum version 14393 (and targets 16299) I get the following exception from the Microso

Answer 1

When I encountered this problem it was solved quite simply - avoid serializing generic collections. It seems to work best to convert your collection to a typed array with ToArray() before serializing.

Answer 2

Given that your package has both UWP and Desktop components, you will need to use the VS Packaging Project for creating the .appxupload file for Store submission.

For more info/examples, look here:

https://stefanwick.com/2018/04/06/uwp-with-desktop-extension-part-1/

https://blogs.windows.com/buildingapps/2017/12/04/extend-desktop-application-windows-10-features-using-new-visual-studio-application-packaging-project/ (see example #3)

The Store no longer accepts packages with mixed UWP and Desktop .NET binaries that have not been created with the proper packaging project. This is to ensure the UWP binaries get the proper .NET native compile in the cloud (which is not applicable to the Desktop .NET binaries). In your case what happened is that the .NET native compile was skipped in the Store, resulting in an invalid package as the declared dependencies don't match the content of the package. We should improve our error detection here, so that we notify you right at submission time that your package is not good and needs more work.

If your Win32 EXE is not built in VS and you just want to include the binary in your UWP project you should still use the Packaging project. Make sure the Win32 EXE gets dropped into a subfolder of the package. See screenshot below for this type of project structure.