Try performing a full reinstall of the game, following the directions below:
1) Back up whatever important files you want (taunts, screenshots, etc.)
2) Uninstall Soldat
3) Delete any remaining files in the Soldat folder
4) Restart your computer
5) Reinstall Soldat
6) Restart again for good measure
7) Test to see if Soldat now works properly
8) Replace backed up files if so