UWP Compilation error with .net native compile option enabled : Internal compiler error: Specified cast is not valid

Karthik Raman 31

I have a UWP project where build works in debug mode but build fails in release mode where .net native compiler is selected. The UWP projects has many external third party libraries like RTSP client sharp, .net media foundation. The error shown is

"
1> Processing application code
1> Computing application closure and generating interop code
1> Loading 84 modules...
"some warnings displayed....
C:\Users\kR.nuget\packages\microsoft.net.native.compiler\2.2.8-rel-28605-00\tools\Microsoft.NetNative.targets(801,5): error : Internal compiler error: Specified cast is not valid."

It doesn't say where the error is.

I tried various values in Default.rd.xml but I can't get rid of this error and I don't think this is the right way of by-passing the error

Attempts 1)Changing Dynamic key to Public or PublicAndInternal didn't help. 2)When I removed I get different error "Internal compiler error: Type 'MediaFoundation.Misc.PVMarshaler' was referenced in method 'IMFAttributes.GetItem(Guid, PropVariant)', but was not found necessary by analysis." This goes away when I re-set dynamic key to Required All or Public or Public Internal 3)Code walk through: I did some basic code walk through. I assume it might be related to some cast but it is very time consuming to go through all the code to figure out the location of error.

We will be needing our app in windows store and hence we can't uncheck .net native compiler mode

Questions) 1. How do you get the location of error: Internal compiler error: C:\Users\kR.nuget\packages\microsoft.net.native.compiler\2.2.8-rel-28605-00\tools\Microsoft.NetNative.targets(801,5): error : Internal compiler error: Specified cast is not valid." 2. Any clues on where the issue can be and how to proceed? 3. Any settings I can use to ignore the error as the build works fine in release mode after disabling .net native compiler

Richard Zhang-MSFT 6,936 Reputation points

2020-03-20T02:06:12.793+00:00

Hello, in order to eliminate the impact of the third party library, you can try to create a new blank UWP project, install the third-party libraries involved, and try to generate Release. If you can reproduce the problem, you can try to remove the package one by one, locate specific reason
Roy Li - MSFT 31,826 Reputation points Microsoft Vendor

2020-03-26T02:40:08.57+00:00

Have you solved your problem?
Karthik Raman 31 Reputation points

2020-03-26T20:03:53.03+00:00

@Richard Zhang-MSFT @Roy Li - MSFT

Sorry for the late response. I did as you suggested. And I figured that the issue happens when I add media foundation .net library as a reference in empty uwp project.
Library path: https://github.com/alexx-grand/Media-Foundation-.NET
(The above code is migrated version of MF .net https://sourceforge.net/projects/mfnet/files/mfnet/ to .net standard 2.0)
If I just add the library project to my solution, it compiles. Issue happens only if I add a reference of the above third-party library project in my empty uwp project.

Why does the issue happen only when I add a reference of third-party library in my project and not when I just add the third party project in my solution.
Can you suggest on how to proceed? How do I isolate the source of the issue?
John Torjo 861 Reputation points

2020-03-26T23:55:15.063+00:00
Let me shed some light here - this will NEVER work. I've ran into the same issue with MediaFoundation.net library, and with Naudio library.

MediaFoundation is using some DirectX API that the WinRT gods don't allow. Same for Naudio.

As long as you use any library that will use some DirectX API / windows API with p/invoke that MS doesn't like, you'll run into the same issue.

So you have 2 choices:

You drop the MediaFoundation lib

You don't publish to MS Store

Personally, I would recommend the latter, but it's up to you.
Karthik Raman 31 Reputation points

2020-03-27T10:16:27.527+00:00
Thanks a lot for explaining this. I will decide to not publish on MS store. It is too late to change implementation and find alternative to media foundation.
However I am just concerned with process of sideloading UWP apps. User has to do these 3 steps:

Modify settings: Allow apps outside windows store to be installed

Install the certificate which signed the app and add it to trusted people

Install dependencies.

On #2, do you also share the certificate with app package and ask user to add the certificate. Or use some standard certificate which most users have already have in their PC. Is there anyway to skip this
On #3, I will try what you described in the link https://github.com/microsoftdocs/msix-docs/blob/master/msix-src/app-installer/how-to-create-appinstaller-file.md
John Torjo 861 Reputation points

2020-03-27T11:20:27.6+00:00
You're welcome!

About the 3 steps:

It's not needed. This has been the default for more than 1 year. Don't remember the exact Win10 version that allows this by default, but you can safely assume it's pretty much everyone.

Yes, you will need to get a sign certificate - it costs about $100/year. I've got mine from https://sectigo.com/ - please look around, and make sure you buy the right one (it's for digitally signing apps). There's no way around this.

There's no need to install any dependencies if you properly create your .appinstaller file -- please read this carefully https://learn.microsoft.com/answers/questions/4027/uwp-cant-install-signed-application-non-ms-storeco.html
Karthik Raman 31 Reputation points

2020-03-27T11:35:03.41+00:00

Thanks Jtorjo. For #2, once I purchase a certificate and use it for signing, the user still needs to download the certificate and add to trusted people. Is this right? Sorry I am just new to this certification stuff.
John Torjo 861 Reputation points

2020-03-27T12:40:28.203+00:00

No - the whole point of a signed certificate is so that you are trusted.

So once you sign with a trusted certificate, the user will just download and install your app.

A word of warning - it's not gonna be very trivial to sign, but you'll get there. Once you manage to do it, it will work from then on. Once you acquire and download the certificate, you may need to convert it into another format, and then use it to "Publish" (the second step, "Select signing method" -> you'll use the second checkbox, and browse for your certificate.

Good luck!
Karthik Raman 31 Reputation points

2020-03-27T13:32:32.893+00:00

Thanks I will try as you suggested. You saved me a lot of time
John Torjo 861 Reputation points

2020-03-31T19:05:15.44+00:00

Awesome, I hope it all works out for you!