Thanks for your response.
We are actually updating the same InfoPath client form in the same document library with task list metadata in view 2. Thus, we've set up a data connection that allow overwrite if file exists for that purpose. When the form is opened and it has been submitted previously, the view will be switched from view 1(entry screen) to view 2 (read only view) automatically.
When view 2 is opened, the task list metadata is populated and the form is updated in document library immediately, however, we got the error. Any ideas?