It should be obvious to the user on the "Execution Plan" tab if a query error prevents retrieval of the Query Plan.
- Executed a user query. The Execution Plan just showed the original SQL and nothing else...
- Further examination of the server log showed plan debug output, but there was a source error on execution
- I switched over to the "Message Log" tab in designer to find the message "An exception occurred fetching the Query Plan"
Request that the Execution Plan tab show a problem message, instead of just showing the original SQL.