java.sql.SQLException: ORA-20005: Task is modified ORA-06512: at "ORABPEL.WFTASKPKG", line 92

I was frequently getting the following error while running my sample BPEL process which contains two human tasks,
java.sql.SQLException: ORA-20005: Task is modified ORA-06512: at "ORABPEL.WFTASKPKG", line 92

My BPEL process looks like the one as shown. It consists of two human tasks Approvals 1 & Approvals 2.

Approval 1 Human Task looks like the one as shown. There are two approvers dynamically picked up at Runtime from the payload

Approval 2 Human Task looks like the one as shown above. It has one approver "Approver 3".
The task history of Approval1 human task was included.

If i provide an input similar to one as shown, i was getting an error.

java.sql.SQLException: ORA-20005: Task is modified

ORA-06512: at "ORABPEL.WFTASKPKG", line 92
ORA-20005:
ORA-06512: at line 1

The reason why i got an error is because the process flow expects a valid Approver 3 username but it was not able to obtain it. The moment i provided a valid username to the Approver3, the error vanished.