When the highlight key is pressed, the nearby players that would be highlighted, are highlighted but the entire screen goes black and the highlighted player is visible, no terrain is properly rendered just an entirely black screen with just the highlighted player visible; for the duration the highlight key is pressed.

Happens in 1.8.1-pre4 with AMD Catalyst 14.9:

OpenGL: AMD Radeon HD 5570 GL version 4.4.13084 Compatibility Profile Context 14.301.1001.0, ATI Technologies Inc.