Guys! I had exactly the same problem on yosemite so deleted my minecraft folder after backing it up and it hasn't happened since! I then put my worlds and resource packs back along with server.dat and it all works! Hope I helped! EDIT: It works for a while and then it comes back 😞 EDIT: Fixed in Yosemite Public Beta 3
Daniel Stone
Guys! I had exactly the same problem on yosemite so deleted my minecraft folder after backing it up and it hasn't happened since! I then put my worlds and resource packs back along with server.dat and it all works! Hope I helped! EDIT: It works for a while and then it comes back 😞 EDIT: Fixed in Yosemite Public Beta 3