Basically. I've been playing on Minecraft classic, Single player through Minecraft.net and it was working fine for a few weeks allowing me to save and load various worlds I had or was in the process of creating from the files saved on my laptop hdd. (because in classic saving online isnt available)
and literally I go on to play a couple of days ago and I click load level as I normally would and it doesn't load nor if I were to start up a new world would it save either.
I'm confused by this (obviously :P) and if theres a reason and a way to fix it would be great. Getting rather grouchy from lack of building ;(

any help would be absolutly great. Thanks