IBM BPM instances are in completed state but tasks are Active

Due to a program error there might be a scenario when instance is in completed state but the task is in received state.

there are 3 Ifixes you have to install to get that solved. Below are links to technote for them

https://www-01.ibm.com/support/docview.wss?uid=swg1JR53167

https://www-01.ibm.com/support/docview.wss?uid=swg1JR52533

http://www-01.ibm.com/support/docview.wss?uid=swg1JR57381