When you alt-tab out of the game and reenter a show error may occure. The whole screen is white. Overlay objects (such as menu, waypoint, GPS, map, inventory etc.) are still displayed correctly but the rest of the world is blank.
On some animated objects like players or vehicles some of the outter lines are displayed in some strange inverted (blue-black) colour at least if they are very close to the player.
When exiting the current game (and lobby) there seems to be some sort of refresh and the world in the background reappers.
However changing your resolution or video settings does not help...