@opsadmin - I just ran into the same problem. It happened immediately after I changed the Apps available to Teams. Not only do I get the same error you have, but I am now locked out of making changes to the apps. I suspect I've somehow removed an app that Teams needs to operate correctly.
Demo environment for me, so I've not bothered to contact support. But let us know what you hear (and feel free to share what I've shared if it helps with tracking down the problem).
