When I'm playing minecraft 1.8, to 15w46a, I crash then the message: "AL lib: (EE) alc_cleanup: 1 device not closed Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release"
I do not know how to reproduce this. It usually happens randomly.
This renders some of my worlds unplayable.