Just started seeing this when trying to activate Sys Optimizer.
Mojave 10.14.1 on a Mac mini.
It’s not preventing playback but there’s a little stuttering, presumably because Sys Optimizer isn’t fully active.
Any suggestions? Thanks!
Try trashing your sys opt preferences
Close A+.
Go to the Main Library Folder… PrivilegedHelperTools folder…
Trash All the files in that folder from A+
(that folder install SysOptimizer).
Restart Mac. Restart A+.
Play a song, it will ask to reinstall sys opt…
Hoping will be good now 
Do you have any fix for this on Big Sur? Cause theres definately no PrivilegedHelperTools. I didnt even know people still us mojave… lol