IDOC is created with status 51( application document not posted)

Hi experts

iam working on File-IDOC scenario, when i test the process the XML message is created with no errors and

but the IDOC is created with status 51( application document not posted)

the details error shows:

An error occurred in CALL TRANSACTION USING or CALL DIALOG USING

during a synchronous update.

The error was caused by the transaction VA01.

previously i used same test data that time it was working fine,

please tell me how can i fix the issue.

regards

vasavi