I’m not sure how to see the agent output when it runs the plugin but I ran the mssql.vbs plugin manually on the server while check_mk showed the “UNKN - Item not found in agent output” error.
A message box appeared listing each section. A message box then appeared for each of the service checks. There were no errors.
Here is what the check_mk web interface shows when this occurs. Other sql server checks seem to run fine.
cheers
jc