Alright, here it goes.
When I'm launching MTA and thus map Editor, I'm getting that boxed message with the loading and so on, then I get the loading page such as in the solo game (everything normal), and suddendly when I'm about to acceed to Map editor, I got disconnected and accordingly thrown back into to the menu with the following error message :
" San Andreas files have been modified "
If it's about Game Mods, I've tried without and it's just the same, and I know people who uses mods and actually CAN start the editor, I tried to reinstall the game aswell numerous times.
Thanks for your help.