Depends on what your server is installed on but generally for Windows/Mac/Linux just uninstall and reinstall older version . ( But do not delete PMS folder which contains your database or advanced settings file/registry which has your server ID)
Gotcha. Now…the hunt begins for an older version for this brand new Windows server/system I installed last weekend. 
Okay, all. For what it’s worth, I uninstalled the latest version of PMS and found v1.22.1.4228. After reinstalling this and refreshing music library metadata, Mood, Styles, and Genres are getting repopulated.
I forgot to take a lesson from the world of I.T.: NEVER auto-update. Download the updates, store them, and wait a week or two until you’re sure you don’t hear any screaming. 
Thanks for the guidance, @BigWheel!
Thank you very much for keeping us in the know.
I am having the same issue as well. Within the last two weeks, any new music I have added to my library only obtains metadata for artist description. It does not obtain metadata for style, popular tracks, mood, or related artists. I use ‘prefer local metadata’ and supply my own years, posters and genre. I can confirm that this is a new issue recently, and my library used to obtain this additional metadata in addition to what I supplied manually via local metadata.
Add genre radios scan dont work, a mess
AFAIK those are also fixed in the same 1.23 version as those use the Mood etc tags to generate the radios.
Thanks god I found this thread, was going insane searching the forums for something similar and also started a thread thinking this could be a last.fm agent issue.
Waiting for the 1.23 version aswell.
Just updated to version 1.23.0.4438 and refreshed metadata for one artist: it seems to have been fixed.
Also updated 1.23.0.4438-5eef0fd80 on docker on Unraid server, and seems to be fixed now.
Thanks god its fixed. Back to work now, refreshing the whole library 
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.