Not sure the Junk filter is working. I reset the training data (bad idea apparently) and it keeps asking me about the junk status of the same senders over and over again. Plus, the log is always blank. 
So is the Filter log. 
Okay, try opening the Config Editor.
Search for browser.tabs.remote.autostart
Toggle the preference to false and restart Thunderbird.
Check your junk filter log.
Fixed the missing data in my Message filters log.
cool. seems to have fixed the log! 
now, if we could just get the apparently short-term memory training problem to stop. 
well, the log appears to have been fixed in the latest beta, cool 
, but I still think the learning is broken. Nothing is getting marked automatically for me and I’ve been training it for a couple weeks.