When seeking help you should indicate f PC or Mac. Their file and path systems operate differently.
Im using GA5 and am investigating how the librarian operates to display its info.
The problem you’re getting is definitely down to paths used by Groove Agent and its storing of VSTsound files and probably how shortcut (pc) or alias (mac) files are located when the librarian moves files. GA will need either the original file in ts contact VSTsound content location (there’s more than one if you use multiple steinberg products e.g. Halion. Cubase etc.) or a shortcut / alias file in that location which points to the actual VSTsound file.
Cheers
David