Deponia - Rufus flashes?

A friend of mine wanted to play the first part of the game Deponia on his laptop. So far everything went great until after the cutscene in the Rufus the ground was chased after the cruiser, at the entrance of the city where e.g. The cop is. However, Rufus flashes and is not there most of the time, the subtitles are in the top left corner. What can you do there?

No idea, reinstalling would be an option