Hi, I am trying to insert one record into database using Write To Data Stor

StackOverflowError would indicate a problem with your JVM. Have you set your JBoss JVM settings according to requirements? Do you need to restart JBoss after the failure? Does the error occur every time you attempt the write?

Hi, you can see my settings in attached files. This issue is not causing any problem with jboss or other processes in appian. It occures only in this process. One reason I can think of is that maybr complexity of our maped to entities database is too much for appian. We mapped near 300 database tables as entitites including references between them so sometimes there could be dozens of tables related to the the table that we are working right now. As I profiled sql server I seen that appian is producing select and empty (with the same data) update statements also on related tables deep in to table hierarchy.

standalone.conf

standalone.conf

I do not think your whole schema matters in this case, although I would suggest keeping the CDT structure simple (no deep nesting), otherwise it becomes really difficult to operate on the data. Please submit a support ticket, they will need to investigate further?
Have you tried writing without Polish characters? It would rather weird if that was it, but it is easy enough to try.