It looks like one of your savegames got corrupted for some reason - if you send it to me, I can have a look at it, although I cannot promise I'll be able to fix it. First we need to find out which save file is corrupted:
*Open up Windows Explorer and type %appdata% into the address bar up on top, then find the subfolder called GD_RPG and open it
*Inside, you'll find a number of files called Autosave.rxdata, Save1.rxdata, Save2.rxdata etc. Make backup copies of these files (by copying them to your desktop or somewhere)
*Then, delete the files one by one and try starting the game after you deleted each file. If you're able to start the game without the error message, the last one you deleted was the corrupted file. That's the one you want to send to me (from the backup copies), send it to
support@defaultgames.de, and I'll see what I can do.
If you're lucky, it may be the autosave file that was corrupted, and you'll be able to continue from your regular savegame after deleting the autosave file. Even if your main savegame is corrupted, you should still have a working autosave file from the city entrance of Sbrodj, so you won't have to start over from the beginning. (you'll have to copy the backup files from your desktop (or wherever you put them) back to the GD_RPG folder first, of course)
If all else fails, I created a savegame with all quests and sidequests finished directly after the boss fight on the Russian Airbase - see here:
http://defaultgames.de/phpbb3/viewtopic.php?p=624#p624I created that savegame so people have a chance of playing through Europe with either Dave or Martine and see all the different sidequests for each character withotu having to start over - it's a bit of a distance from where you are in Sbrodj, but at least you wouldn't have to start over from the beginning.