Hello Ralf!
Thank you for Your answer.
Well, I do of course know this, so I do have one single track section on each end of the 3-field Train number section. So that should be OK. I do have a track symbol 1 directly to the right of this, belonging to another track. Does WDP think this is a Field that belongs to the same track as the 3-feld train number? Could be... The error-message disappeared when I replaced that 1-number With a single track....
Regards,
Per.