Opening the msix file results in an error: "The app didn't start."

I already did. But it can be open normally under Administrator User.

New MSIX install package has been created, please download it from
https://github.com/localsend/localsend/releases/download/v1.10.0/LocalSend-1.10.0-windows-x86-64.msix maybe this will solve your problem.

If possible, try create a new user and login with the new user and see if it works?

Unfortunately, it's not working. The msix file still cannot be opened after clean boot.

Thank you for the update, please share the result of Clean Boot.
Note, when you run Clean Boot, it keep your files and data and just disable services and you may enable them later.

Windows PowerShell
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PS C:\Users\Administrator> DISM /Online /Cleanup-Image /CheckHealth

Deployment Image Servicing and Management tool
Version: 10.0.22621.1

Image Version: 10.0.22621.1778

No component store corruption detected.
The operation completed successfully.
PS C:\Users\Administrator> DISM /Online /Cleanup-Image /ScanHealth

Deployment Image Servicing and Management tool
Version: 10.0.22621.1

Image Version: 10.0.22621.1778

[==========================100.0%==========================] No component store corruption detected.
The operation completed successfully.
PS C:\Users\Administrator> DISM /Online /Cleanup-Image /RestoreHealth

Deployment Image Servicing and Management tool
Version: 10.0.22621.1

Image Version: 10.0.22621.1778

[==========================100.0%==========================] The restore operation completed successfully.
The operation completed successfully.
Haven't tried Clean boot yet.