I've been updating my old MA terrain project with the new editors today. The new error checking routine complained a couple of my fields were too close together, but after I had fixed that it gave the terrain a clean bill of health.
I can run the AH Build Terrain program, but it only works if I leave the "upload terrain to host" box unticked. If I tick that box it says "unable to upload" and asks me to do another "check for errors". However doing this still shows "No errors found. The terrain is now uploadable." Am I doing something wrong or is this a bug?