Thanks everyone for your great help!
Everything works now.
Just some missing answers.
I knew I could search with direct search but the Add cover art edits I found would never lead me to release with CAA data.
I think I did that and it worked!
I wonder why I had to do this, maybe because of the JSON bug.
Changing my CPU would be too troublesome, and I don’t want to have my old CPU lying somewhere or in the trash bin.
I already upgraded my RAM to the the max (4 Gb max is possible on the P5B-BN mainboard of my Asus T3-P5G965). Apparently it’s from 2007, not 2006.