Unable to re-register VSTO Add-in after choosing [Remove] from COM Add-ins window

Question

I am developing a VSTO add-in for Ms Word. Run -> Start (F5) in VS 2017 worked fine.

Today I ran my first tests by publishing the add-in (ClickOnce, generating a .vsto f

Answer 1

So far the best I could do was to change the Assembly Name. This allows the solution to be seen as a different Add-in by Ms Word and to be registered correctly. It works, but this is far from being acceptable..

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Update 1

Now working with fully signed releases, and following substantial testing: this is an issue with Windows 10 only, where ClickOnce is "cut loose" from the VSTO it installed after it being installed for the first time: uninstall your ClickOnce app via the App & Settings panel, and the VSTO is not unregistered from Word; or unregister the VSTO manually, and ClickOnce is unable to re-register it into Word.

The above steps can be undertaken under Windows 7 with no problems.

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Update 2

Looks like this was related to the installation version of Office: Click-to-Run vs Microsoft Store. The issue did not come up with Windows 7 because Microsoft Store installations are not available.

Full response here: https://stackoverflow.com/a/58625402/10794555