Look out for the LocalAppDataPath key
If it exists, take a look at the folder path it points to. This is the place where you should have copied the contents of the Plex data folder from the old server.
If the key doesn’t exist, it means that Plex Server is expecting the data at their default location on Windows.
So you should have copied the data there.
Verify you copied the data to the correct location.
I solved it and it was a stupid mistake. I didnt stop plex when packing up the plex media server and as it was in use, it couldnt pack in the library db which is pretty much the most important thing when it comes to, you know, libraries. I copied that in and worked instantly.