Cannot install UWP app: Unspecified error

Question

When trying to install the appx file on my customer's machine (off store), I get the following error that says "MyProj.UWP installation failed", Reason: Unspecified error.

The app does install properly on my machine.

Any clue how I can trace down the error? The app wasn't installed on the target machine, from what I checked in Apps & Features.

Update

Thanks to @Nico's answer, the unspecified error is gone, now I'm rather having this error:

Ask the developer for a new app package. This package may conflict with a package already installed, or it depends on things not installed here (package dependencies), or is made for a different architecture (0x80073CF3).

I selected Debug - x86 and Any CPU when packaging the app.

Answer 1

If your min target version is higher than the customer's machine OS version, it will fail to be installed. Please recreate app package with minimum sdk version to match the customer's machine.

Answer 2

You can also run into an issue where the dependencies have updated without you noticing. I've found the "Get-AppxLog -All" powershell command useful, also it might be helpful to check the page "Troubleshooting packaging, deployment, and query of Windows Store apps".

If you create an Appx Bundle then the dependencies will all be in a folder next to the .appxbundle file.

Answer 3

The solution to the second half of my question (see update), was selecting "Generate app bundle" in the VS package creator, then installing the dependencies manually on the target machine (from he generate Dependencies folder supplied with the package).

Afterwards, the app installed without issues.