Hi Andrey,
I am facing the same issue and followed your suggestion i.e. implemented the WorkItemHandler to insert a space when comment field is empty/null.
In fact I filled comment field in the process definition, but still I am facing the same issue.
I am trying to integrate jBPM5.3 with existing legacy app which is using JPA/local TX and I have configured JPA for both process/session related table and also task related table.
When I run the applicaiton and start the workflow process, it is inserting data in session and process related table, but it is failing while inserting I18NText data and unable to rollback the Tx.
do you have any further suggestions to fix this issue?
Appreciate your help.
-Naidu