Now, that was more informative. I don't want to be rude or anything like that, sorry if I was, but that's (in my opinion) is at least a point we can start from.
Honestly support is not an easy task and especially the errors concerning the Map Editor can't be answered with a standard sentence. So we have to rely on the data given us by the users. So we decided to create a template for support threads to get this data. When this template is not filled in correctly we probably can't help you. This is the fact, why we were pointing towards the template in the first place.
BTW the second error message says: "A tile could not be loaded or is corrupted. Do you want to delete it?"
Maybe there's such a big error the map editor cannot even load it?
Ok, the error message is a big part in the puzzle. Basically if you get this error message, you need the files from a back up. The Map Editor is capable of cleaning the map and get a consistent data basis. When this fails, the tile has to be removed permanently. You only can replace it with the same file, but in an older version.
Do you know, is there any size limit that the map editor doesn't really likes to load a tile file above?
There shouldn't be a reachable file size. The effects of having high size tiles affect the performance and the loading times when changing the tile in the simulation. The editor should also have a worse performance, but I don't think 200 MB are enough to crash the editor. A key fact is, that the tiles nearby are also very big. Maybe this changes the equation.
To get in touch with some numbers, I had high sized tiles in my map Duesseldorf as well. The biggest tile had like 130 MB. On a medium PC with like 4 or 8 GB RAM, the map had performance issues. Janine has an old laptop to also check such oncomming performance issues, you'll find the specs somewhere in the lexicon/writings about minimum PC specs. I decreased the size of this tile by 50 % simply by optimizing all splines and rails.
Another effect we recognized were the loading times for the tiles when not stopping at tram stops. I've reworked the ties to get a better performance and smaller loading times in the editor and in the simulation.
A normal tile should not hit the 50 MB mark at all.
Also, what thing can he do if the map editor doesn't open those tiles? Delete the tile files and rebuild the content of it, or nothing?
The file contains the terrain. If you delete the file, the terrain is gone and all information about it too. If this happens, you are basically screwed. Because of simulating the globe and its round shape, every file is unique and can't be replaced by an other tile file.
Greets