Msix more file install

lcdiet 

While you'd need to debug to be sure, in all likelihood the source code expects the working directory of the process to be the folder that holds the exe file, and the code references the file without and folders.

Traditional installer shortcuts usually will cause the process to start with the working directory of the process to be that folder, but under MSIX -- by default -- start menu launches will set the working directory to be the Windows\System32 folder.

When source code is not available, we usually solve this by adding PsfLauncher from the Package Support Framework.  Your package start menu item should point to PsfLauncher, which is then configured to launch your app and set the working directory as you'd like.

With source code access, you can modify your code, either using the executingassembly folder (if .net based) or by adding in the path the to exe in a registry string which the app reads.