VSTO: The Customization Cannot Be Installed

Got this strange error today with an Excel add-in I’m working on:

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 issue.

Google didn’t turn up any results on MSDN.  So I fired up ProcMon.exe to try to isolate the source of the issue and what it was trying to load.

Turns out that it was trying to read values from a key at:

Deleting this key fixed the issue 😀

Still not sure what caused the issue in the first place, but this is a quick any dirty way to resolve it (for now).

You may also like...