Add-on Update Fails, no documentation

When customers try to update our add-on, it fails without a useful error message (except that the add-on host server replied with a 400 status).

There also doesn’t seem to be any documentation on which requests are sent to our servers during a manual update, so it’s impossible for us to get to the bottom of the problem.

We’ve been recommending that people uninstall and reinstall, which works great.