Some of our users in our organization has started to report a strange error when installing our product (product details redacted from the screenshot):
The original error message in English is "Installation directory must be on a local drive".
Changing the path to something without spaces, alternate root folders or even other physical drives on the machine changes nothing. The installer still insists that the path isn't a local path.
This installer is created with WIX, and the specific step in the process is created with the custom action
WixUIValidatePath. A bug has previously been submitted, that also indicates that the error is related to restrictions on the installer (thanks to peterflynn on GitHub for pointing me in that direction).
The problem only occurs on some computers, and it appears that no one has the issue in Windows 10. I have not been able to test if it occurs in other Windows versions a part from 8.1, as that and Windows 10 are the only versions we run.