error while executing standard workflow 21500001

Hi experts,

      I am trying to execute standard workflow 21500001. It is giving an error :

1.Task started under work item ID <> (current status: Error)

Message no. WZ703

2. there after i checked tcode SWI1, it shows-----

agent - no current processor

3. then i went to tcode PFTC->agent assignment-> maintain-> attribute->attribute

it gives an error  -----   pls position the cursor correctly

4. then i checked tcode su53 , it displays   -----  failed HR structure authorization

need your assistance, Kindly reply asap

Thanks and regards,

Ritu