Everytime I start up Minecraft, the white loading screen with the bar graphs and minecraft logo takes 5-10 mins to load (usually takes like 20 secs) and then once it gets to the main screen it freezes and says "failed to load character 5". When it does work (5% of the time) and I try to load my world it goes to "updating 1 of 4 packs" and stays at 0% the whole time. Please help.