Weird random minecraft crashes sorta...

Well today for some reason when i opened up magic launcher, it said that it has a new udate, so i downloaded the new update and so then when i launched minecraft and then go on a server, it would crash after a few seconds, well not really crash, it would freeze and then say that java isnt responding, then it would close out... Can any one help me please? I have optifine and better sprint installed if that helps at all, and this didnt happen before...