Purchasing document WF-BATCH blocked

Hi all,

My workflow will give Auto approval (auto release) based on some condition. I am using a method Release of BO- BUS2012. Depends on the amount, it will pick up the release strategy.

My problem is, workflow is giving auto approval (in background) for the first release code. I am looping the workflow, then the second release code comes (I am able to see in log) but the method "Release" gives error and in log it says "Purchasing document WF-BATCH blocked".

Please help what is the problem or I need to execute any other method before going for auto approval for the second release code.

Regards,

V Kumar