Quote from GamingTom
I can fix it by restarting my computer but that just takes too long and is a waste of time, any help would greatly be apreciated!
Strangely enough this seems to be a problem with the flash plugin (though I've only noticed it in chrome). If I close my browser and then start Minecraft it seem's to fix itself. Flash will still work fine, but only if it starts after Minecraft. If your browser is set to stay loaded after you close it then the problem could persist until you reboot (in chrome it happens it you tell it to 'Continue running background apps when Google Chrome is closed' in the 'Settings->Under the Hood' section).