StaleObjectStateExceptions in Old hibernate version

We have been having an issue with StaleObjectStateExceptions in in our hibernate version (3.5.6) against Maria DB.

I am wondering if there are tools in more recent versions with better ways of dealing with them? If so what is the name of the feature or tool, and what version of hibernate should we target? This would help me to justify upgrading Hibernate

Also, is there a good place to go to find a consultant that has experience with our old version?

I don’t think anyone will still be able to help you with that. Hibernate 3 is way too old already. I’d recommend you first update to 5.6.15.Final and when you get there, consider updating further to Hibernate 6.2 to get the latest and greatest, as well as good support from the community.
At this point, we only do critical bug fixes for 5.3 and 5.6. From the community side, right now we only support version 6.2.