Hello,
Sync is crashing in my Syno DS112j, too. Version 2.3.3. I can't get it to run any more. sync.log shows no sign of a gracefull shutdown, I see lots of *.dmp files in /usr/local/bittorrentsync/var, timestamp fits to the time I tried to start it.
If I can help with diagnostic files please let me know.
Regards!