C6 Artist freeze upon startup "Init: Video..:"

Hi all,

from one day to another, without me having installed anything new, C6 Artist does not start up anymore. It freezes upon (something like) “Init: Video File …” - I just know the German description.

Before it freezes, very quickly a popup appears and disappears - don’t know what it says, as it happens too quickly.

Anyone got an idea what to do?

Windows 7 64bit
C6 Artist 64
Core i5
misc. VST Plugins, that all happend to work the weeks before

Thanks and regards,