Cause
You have placed multiple signal definitions or net definition points with different signal names within a signal.
Solution
Possibility 1
Reduce the number of signal definitions and / or net definition points with entered signal names so that only one valid signal definition remains.
Possibility 2
Enter the same signal name at all signal definitions.
If required, start a new check run.
Tip:
The course of signals can be highlighted in color by means of the signal tracking (Tab View > Command group General > Button Signal tracking).