Got this strange error today with an Excel add-in I’m working on:
The customization cannot be installed because another version is
currently installed and cannot be upgraded from this location.
To install this version of the customization, first use Add or
Remove Programs to uninstall this program
Now this seems pretty straightforward, right? However, the add-in doesn’t show up in the Add/Remove programs menu! No amount of clean solution or rebuild would resolve this...