Hello there!
First, in the past few weeks, month the tracks are started to slowly disappear in some places. A meter or more missing from the track but a train goes through it without any problem.
Second, when i deleted some tracks, there were some parts left, wich were undeletable. No matter how hard i click on them i can't mark them, but if i right click on them i can go to their properties, but i can't delete them there. I tried to refresh the terrain multiple times, it didn't help me.