Hi Shayastha
The message you have given is the message that "the workflow has gone in an error".
However, we need to know the exact error to determine the cuase.
Pick the "ID", that is, the work item ID, from the above message, get the screen shot of the workflow log, espicially the technical log with the step history of the top node (header) and the step history of the actual step which went into an error.
Please provide these so we all can look in detail.
Regards,
Modak