VSTO Ribbon disappearing on ClickOnce upgrade

I have an add-in for OL2010 (written in C#) that works great. It loads with no problems on my development system, and initial installations on test workstations goes smoothly.

When I make a change to the code and republish the installation, the ClickOnce upgrade runs, the add-in loads, but the ribbon that's part of the code does not appear. I've verified that the add-in is loaded, so that's not the issue. If I close Outlook, then re-open it, the add-in appears as it should.

Oddly, if I disable 开发者_StackOverflowthe add-in (when it's not visible), it appears. When I re-enable it, it's still there and works fine.

Ideas? I'm baffled. Nothing was changed in terms of my ribbon code, so I'm perplexed.

Did you run your update while Outlook is open?

From past experience, Outlook "de-activates" your add-in if it gets updated. You can restart outlook, or "activate" it from their terrible (almost unusable) add-in menu and it will reappear.

Is this what you are seeing? As a test, close Outlook, then update your add-in.