Transaction is not active error when invoking Sign Signature operation

[greentea87]

Hi,

I am getting 'Transaction is not active ..' error when I try to invoke a process(directly invoked through Workbench) which had a 'Sign Signature' operation as shown in the screenshot below. I have tried restarting the JBoss server, and also tried re-deploying the app, but this problem still persists.

Thanks in advance!