WinUI3 app is not launching

[pbasithmpy]

I am using unpackaged app with winUI 3 framework. And it was working fine. but now I am getting an error saying like below when app is launched. I have installed windowsappruntime installer already. could anyone can help me fixing this

Exception shown in Event viewer:

[DarranRowe]

There is a known issue #2918 with later updates for Windows 10 are having issues with permissions on the files in the Windows App SDK package.

[DarranRowe]

Well, again I'll point out that this isn't a Windows App SDK problem. It is a Windows 10 problem.

Windows 11 has no issues, and this is with the Phone Link (YourPhone) app installed.
The problem stemmed from the fact that when Windows deploys a packaged application, Windows will attempt to save space. It is possible to hard link files together, meaning there is only one instance of that file physically on disk. This is what Windows does for files in the SxS directory too.
Now, it seems as if Windows 10 was hard linking the Windows App Runtime files to the YourPhone files, which contained the Windows App SDK in a self contained form. But when it did this, Windows 10 messed up the access control lists for the files.

Any new release of the Windows App SDK may end up working, but if the issue in Windows 10 isn't fixed then any apps which contain the Windows App SDK in a self contained form could result in the same issue occurring. So, the most important thing is Windows 10 being fixed.

For your post about Remove-AppxPackage failing. The important thing is to reset the ACL for the Windows App SDK redistributables, so removing the Phone app is required to get rid of the potential conflict with the files.
So right now, if you open an administrator powershell console and run Get-AppxPackage -AllUsers -Name *YourPhone*, what output do you get?

The important things to look out for is whether it is actually installed, what users it is installed for, and whether or not it is staged. Also, check if it is provisioned in the image using Get-ProvisionedAppxPackage -Online. If you have successfully removed the Phone application completely, then it is fine if it failed for all users.

Also, the whole reason why I originally stated that you needed to remove the Phone application and completely remove the Windows App Runtime was to reset the ACLs and make sure that Windows wouldn't break them again. That is why it was important to completely and successfully remove everything.

[pbasithmpy]

for Get-AppxPackage -AllUsers -Name YourPhone this command I am getting an output like this

but I am unable to delete the package

[pbasithmpy]

And I tried to built my application in unpackaged self contained mode, but that is also getting some sort of error when I publish the application. WinUI3 unpackaged self contained is not supported?
on publishing I am getting an error saying,
Microsoft.WindowsAppSDK.SelfContained.targets(42,5): error : The platform 'AnyCPU' is not supported for Self Contained mode.
even though I tried to publish the app for x64 platform

[DarranRowe]

Well, trying this out on my system was a pain. The store wasn't offering that version of the phone application to me by default. I had to do... things... in order to get the same version.

Anyway:

there were no issues removing it. The fact that it is failing with ERROR_FILE_NOT_FOUND for you is also curious. I would honestly consider whether the package itself is corrupted and try repairing it.

Also, unpackaged self contained is supported. But I honestly can't say too much about the .NET project system because I use C++.

[pbasithmpy]

Thanks @DarranRowe for help. this was exactly the problem. I couldn't solve that by uninstalling your phone. because it is not always possible to make users to uninstall any application in their machine. So I changed my win ui app to windows app sdk self contained mode. And now there is no clash with any other apps and working perfectly

[gautambjain]

I received the same error all of a sudden. Then I discovered that x86 build does work. But x64 does not. Since then I have been only building x86 version.

[pbasithmpy]

yes. I tried x86 and it is working fine for me. But in my application there is dependency to x64 libraries. so I would need x64 build