I have a WPF app that I am planning on deploying with the Windows Application Packaging Project in Visual Studio that makes the MSIX bundle for installations and future updates. The installer automatically installs the app in C:\Program Files\WindowsApps. This is fine until the program needs to cache some data or it needs to modify the appsettings file since the app does not have permission to get to these resources.
Is there a setting I can change in the packaging properties/manifest so it can install somewhere else so I can avoid these problems?
Indeed, only the Windows can write in %ProgramFiles%\WindowsApps when installing the msix package (by design). If your app is writing log files or other data inside the installation folder it will crash.
You need to either update your code to write to %AppData% or, if you don’t have access to the code, use the Package Support Framework to fix it. You can read more about here: Package Support Framework (aka PSF)
The PSF brings support for API redirection and hooking. Thus, you can fix an app that failed to write a file in the installation folder (this is no longer allowed) and redirects it to a recommended location, or maybe simply update the app’s working directory.