Cause

In the P&I diagram there are several piping definitions (piping connection points or piping definition points) which have contradictory values with regard to the Substance property at a connection.

Solution

1. Locate the respective piping definitions using the Go to (graphic) function from the popup menu in the Message management dialog.
2. Open the properties dialog for each piping definition and enter the same value in the Substance field.
3. Refresh the connections and then start a new check run.