I can’t get the mass editor to work with sonarr v3. I did some googling and found a way to edit the paths at the database level. I’m not sure how safe this is so I backed up my db before I did it.
UPDATE Series SET Path = REPLACE(Path, 'old_path', 'new_path') WHERE Path like '%old_path%';
This is not perfect. I did mess up a couple paths so I had to manually edit them. This helped me identify them
Select Title from Series where Path like '/data/TV Shows%' AND Path not like '/data/TV Shows/%';