Cause

Only a single distributed terminal with a terminal designation is available in the project.

Solution

1. Locate the relevant terminal in the schematic or device navigator using the Go to function from the popup menu in the Message management dialog.
2. Add at least one more distributed terminal to the terminal strip that belongs to the individual distributed terminal and give this distributed terminal the same designation. (Both terminals do not have to be connected in the schematic with an autoconnecting line.)
3. Refresh the connections and then start a new check run.