Cause

In the project there are distributed terminals with different function definitions.

Solution

1. Locate the relevant terminals in the schematic or device navigator using the Go to function from the popup menu in the Message management dialog.
2. In each case open the properties dialog of each distributed terminal and switch the Symbol / function data tab to the foreground.
3. In the Function data (logic) group box, next to the Definition field, click [...] and select the desired function definition for the distributed terminal.
4. Repeat the process for all other distributed terminals, ensuring that all of the function definitions are the same.
5. Refresh the connections and then start a new check run.