As soon as focus is back, it fills the log with this:
[22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:14] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:14] [Client thread/ERROR]: @ Post render [22:09:14] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:09:15] [Client thread/ERROR]: ########## GL ERROR ########## [22:09:15] [Client thread/ERROR]: @ Post render [22:09:15] [Client thread/ERROR]: 1286: Invalid framebuffer operation [22:14:13] [Server thread/INFO]: Saving and pausing game... [22:14:13] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/Overworld [22:14:13] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/Nether [22:14:13] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/The End [22:27:21] [Client thread/ERROR]: ########## GL ERROR ########## [22:27:21] [Client thread/ERROR]: @ Post render [22:27:21] [Client thread/ERROR]: 1281: Invalid value [22:28:37] [Server thread/INFO]: Saving and pausing game... [22:28:37] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/Overworld [22:28:37] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/Nether [22:28:37] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/The End [22:28:38] [Server thread/INFO]: Stopping server [22:28:38] [Server thread/INFO]: Saving players [22:28:38] [Server thread/INFO]: Saving worlds [22:28:38] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/Overworld [22:28:38] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/Nether [22:28:38] [Server thread/INFO]: Saving chunks for level 'YoloCraft'/The End [22:28:39] [Client thread/INFO]: Stopping! [22:28:39] [Client thread/INFO]: SoundSystem shutting down... [22:28:40] [Client thread/WARN]: Author: Paul Lamb, www.paulscode.com [0x7FFC74652FF0] ANOMALY: meaningless REX prefix used # # A fatal error has been detected by the Java Runtime Environment: # # EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffc7aa03924, pid=12812, tid=15176 # # JRE version: Java(TM) SE Runtime Environment (7.0_67-b01) (build 1.7.0_67-b01) # Java VM: Java HotSpot(TM) 64-Bit Server VM (24.65-b04 mixed mode windows-amd64 compressed oops) # Problematic frame: # C [OPENGL32.dll+0xe3924]
Made https://bugs.mojang.com/browse/MC-66614 then found this - Crash log attached.
As soon as focus is back, it fills the log with this: