OMSI cannot start (Label75) problem

I've finally managed to activate my OMSI, but now I cannot launch it.
When started from Aerosoft Launcher OMSI starts, opens a empty window with text Label75 and then exits. If I start OMSI from a desktop icon, the same error message appears.

I've tried to run OMSI in regular and ADMIN mode - no difference.

My system is Windows 7 Pro 64-bit, i5 750 @ 2.66 GHz, 8 GB of RAM, ATI Radeon 5800HD, DirectX11