TLDR: Bandaid-Fix for GetAddonMetadata Error in Wrath Classic 3.4.2 (currently PTR)
Blizzard changed something and broke a lot of Addons. On the current PTR you will get a lot of LUA Errors stating that something went wrong calling the global "GetAddonMetadata".
Until the Addon authors implement a fix for their individual Addons you can use this simple Addon to fix all broken Addons temporarily at once so you can play the PTR in peace.
The Source for this Fix was here:
https://twitter.com/Thdlock/status/1641472349324169219?lang=de
I just put it into an Addon for simpler use.
Enjoy