I have an Outlook Add-in. In Outlook 2016 (Office 365 desktop version) it will not load. 32 bit Office install on Windows 10 64 bit. It appears that the VSTO runtime itself is not loading. The add-in does not appear. It doesn't appear in the disabled add-ins, nor in the Manage Add-ins anywhere to be enabled.
The add-in registry entry for being always enabled is correctly added. I have verified that the correct .NET version and the VSTO runtime are all installed. I have set
VSTO_SUPPRESSDISPLAYALERTS 0
VSTO_LOGALERTS 1
and receive no data back from them.
I have also verified that the registry keys are correct. LoadBehavior is set to 3 and Manifest is pointing to the correctly installed file.
What is even more curious is that it did load at one point and worked fine, but seemingly all of a sudden it will not.
Has anyone run into this or know anything I can check to see what is going on?
In the event anyone runs into this, here are the steps used to solve the problem for me.
It's a pain, but it worked.