when I click on the "seen" button (below Mini Statistics and above Marked) XMM gets "stuck" with the window "Loading values in Grid, please wait...". CPU usage is 100% on one CPU. After 45 minutes, I gave up waiting and closed XMM.
ok, tried again... at 48 minutes, it came back to the list... "Applied Filter <blank> and ([Seen] = true)" but the list was empty. I have 1251 movies and 598 seen.