Hi Resfu. Two things to check. First, when you load up bring down the console (ESC or ` key) and type: logfile 1. This will give the ufoconsole.log more output sometimes, but it may only work if you have debug version of the game.
Second, you can check the crashdump.txt (or log?) file, which I believe is either in the base /ufoai/ folder or the /ufoai/base/ folder. If you're on Windows, this is no the APPDATA folder where the saves are stored, but actually in the game's installation directory.
You can also attach the save file so that someone can test it themselves.