I've been working on lifting the track segments by manipulating the number values in the world files and with one exception I seem to have done it. I'd guess I lifted nearly 3000 track segments in one fell swoop -- most by 1m, some by 0.5m, and 3 tiles were left as-is. This was done in Excel and once I figured out what to do the process to do the lift went very quickly (if anyone wants to know how I did it, just ask). The difference in the lift height means I'll have to re-lay some track in a couple of places. I prepared for this by breaking the segment connections at the particular tile boundaries where the lift amount was different.
The one problem left is I had misjudged the starting point of one track segment and put the break in the wrong spot. This has left the start location of that one segment lifted 0.5 and its end connected to a segment that was lifted 1.0m. RE gives this message to both track segments: "Adjacent track pieces not loaded. Cannot select track piece".
I don't yet want to go back to my backups (where I would simply change the break location) and redo the lift on those two tiles... I'd to see first if deleting the two track segments in the tiles would solve it. And if that's not a good avenue, I will go back to my backups and do it all again.
So the questions are: Has anyone seen this same message? What did you do to create it? What did you do to fix it?