You have certain splines on separate layers. The easiest way to fix this is to simply merge down everything to the Route layer.
If this is not an option, you will need to manually find the spline that is on the wrong layer. Toggling the visibility on and off may help, but it's still a tedious task.
Sometimes, the offending spline might not be a track at all. Follow the corrupted track to it's start/end-points and look to see if it's trying to connect to another spline, maybe a road or fence for example.