Bogdan Flueras commented on an issue
Hibernate ORM / Bug HHH-7688
Bug in NonBatchingBatch makes session ununsable after failed transaction
In NonBatchingBatch.addToBatch() are some bugs (missing try...finally) that leaves the class in an undefined condition if the statement there fails. In addition, statements are not closed on error.

I have attached a project that shows the bug and contains a fix.

Here's my complete description (which you will also find in ShowBug.java):

        /**
    ...