Continuing building though the harsh environment of the desert. A fool's errand? A hard task, undoubtedly.
Especially when these developers tools of ours acts up and decides not to work properly. It likes things done in a certain way, so it's not a good place to do testing, not in your current project. There's a chance the project ceases to work properly, sometimes not even loading anymore.
There's four things i can do, to try to repair a project:
Look at the error log to see if there's any error that might be related to the part of the map that broke and go from there (there's always errors, even in a blank project; the tools were released a bit like a feral baby was thrown into the wild, features gutted);
Start deleting random bunches of objects from the map, testing after each delete, in hope to find the culprit object responsible for the breakage;
Go through the project's folders to find any files that are related to the issue, and get those files from a working project, replacing them in my current project, and hope that fixes it;
Port the entire project to a new one. This is like playing Doom 2, but not having fun; hell on earth. It consists of copy-pasting all objects i've placed on the map, preferably by type, and start grouping them into small groups no more than a couple thousand objects each (because the tools doesn't like big groups either). Then, the terrain. No simple export button exists for the terrain, so this is done in the hackiest, error-prone way ever. Then, copying the script for the map (is how i create objectives, control items on the map, etc). After all is gathered, i then create a new project and "import" the new terrain, the groups of objects, and paste the script. I then break the groups up so that all objects are back onto the root, so to speak, so the script can correctly target them, and prey to the heathen gods this process didn't break the new project as well.
So, my project just broke, and it happened while i was doing the sand/road transitions; normals from one of the textures isn't being applied.
Luckily, i just had to delete one of the materials i was using (which had the wavy sand texture applied; the one that had been working all this time), make a new material, re-apply the sandwaves texture, and re-paint the terrain.
As the map gets bigger and more things added, the more prone it is to break, and the more work to fix. It's just the way it is.
Something's don't ever change.
It's just the way it is.