Error in IDoc extension

Hi Abappers,

I have implemented the user exit for outbound IDoc of message type HRMD_A

I have alo extended the IDoc_type and populated the segments in the user exit.

I am getting the error while executing tcode PFAL for sending HR Data as a popup

Internal error: Program read table idoc_structure,

command data_select_for_block, argument ZPAD25

How to corect this error?

Regards,

Rahul