If could please more info which route and scenario you are having problems with we can assist you better.
You are driving a train and the points/switch for the line coming in to your track is not set for your train and you get the message. This happens if you are driving over a section of route where you have to change the points. Go in to the 2D map by pushing the 9 on your keyboard I'm driving the train in Red and the path of my train has caused the track to be shown in Dark Blue But the first set of points are not set correctly as the heavier lighter blue points to the next track Click on the Blue Dot, circled red, and that will change the points to the next track. Peter
In addition to what Peter says above, you can sometimes get the error you posted about on AI traffic if the scenario has errors. If this is the case the usual best way of getting around it is to edit the scenario and simply remove the offending consist
This Just happened in addon MLV CAREER Scenario: Part 1: London to Brighton - near the end, about 1 mile out from London Bridge - Typical! - I was doing really well too!
Someone asks a question here, (the OP) two ask for more info and two people take the time to give answers. With no response from the OP I don't know why we bother.
Because if the same question is asked by someone else we can point them back here, or even better they can search and find this themselves meaning they don't even have to ask