For some of our loans, when we try to repay, tomcat starts to use 100% of server resources.
It can be resolved only by restarting tomcat, then undo disburse loan and create a new loan.
When we create exact same loan again to replace the broken one, it work fine. So it does not seem to be triggered by any of the parameters of the loan.
We had this happen in about 5% of our loans.