PersistenceException

I finally managed to work out why I was receiving the dreaded “PersistenceException”.  There’s not a lot of helpful information surrounding this one, you just get:

Microsoft.XLANGs.Core.PersistenceException: Exception occurred when persisting state to the database

Most of the posts I Googled for were incorrectly diagnosing it as occuring due to no subscription being set up in the Message Box.  However, this was on a late bound Send-Receive port, and the subscription appeared good in the Group Hub.

Finally, I worked it out!  It was being caused due to a duplicate subscription in the Message Box.

I had another Orchestration that was direct bound on the same Message Type that I was trying to send via the Send Port.  Somehow, this causes BizTalk to get in a huff, but not really give any worthwhile error information.

So, whenever you find yourself with a “PersistenceException”, try looking for a duplicate subscription.