I just upgraded Spamassassin, and low, after I restarted it I received an error message while trying to start Spamassassin.
Per the article below, a simple
at the command line updated the Spamassassin rules. Then it would start like normal.
Did this help you out? It took me a few days to piece together all this information together, I hope this saves you some time (who knows, maybe the future me will be thankful I wrote this down). Let me know your thoughts. email@example.com