MQ MQHRF2 format error

We are using webmethos IS 6.0.1 with SP2 and webSpheare MQ adapter 6.0 with SP1. Getting below error when tried to read/get any message from A MQ queue with MQMD header.Format is set as “MQHRF2”. [ART.117.4002] Adapter Runtime (Adapter Service): Unable to invoke adapter service AutoDecision.pollers.listeners:ReqQMQheader. [ADA.600.1055] Exception caught Get : null null

Any help on this would of great help.