Services Procurement: Error recieved in OTL when bringing time into Purchasing

Hi i have recently set up services procurement and i am recieving an error when i run the Retreive Time from OTL concurrent in Purchasing.

Steps:

Create a contractor request in iPro --> approve req --> autocreate to Purchase order --> create contractor request --> add contingent workers transaction controls --> create FND profile --> log in as person to enter time --> approve time --> run concurrent request: Retreive Time from OTL

the error i am receiving is

Your request could not complete because an earlier request is still being processed. Either submit your request later, or contact your system administrator.