Board Thread:Bug Reports/@comment-78.157.23.54-20150222103516/@comment-25565811-20150222105956

Perhaps too less memory. Try the following:

If you have a PC, press control-alt-delete (all three keys together). Select the task manager to see all the task which are running. Kill tasks, you don't need (careful, this could crash your computer).

You'll find at least two java tasks the bigger one (for me it's about 1.000 MB) is Minecraft itself, the smaller one (for me about 200 MB) is the laucher. After minecraft started, you can kill the launcher, you won't need it any more. You just loose the possibility to watch the error protocol and when MC crashes, you'll have to restart the laucher again.

You can also close all your windos manually.