Files restored to Starbound's workshop folder won't appear ingame
I previously backed up all my Starbound mods needed for a save, and now some files are corrupted and I want to restore my copy of the contents of the workshop/content/211820 folder that I saved on my Google Drive. When I put them back into the 211820 folder, Steam does not show the mods as subscribed, and they do not appear in-game.
Verifying game integrity and restarting Steam or my computer has no effects.
You likely need to subscribe to the mods again in the Workshop. That should trigger Steam to look for their respective content in said folder.