Error While create purchase requisition and return goods

Dear all,

My user is having some issue while creating purchase requisition from sourcing responsibility.  Also while returning a requisition, getting error

At the returning of the Po to requsition it brings the Error Page 

You have encountered an unexpected error. Please contact the System Administrator for assistance.

It brings Error Purchase Order Creation could not be initiated. Please check with your system administrator.

I having the above 2 errors from sourcing.

Kindly please forward my issue to sourcing.

Kind Regards