Fatal freezing

Every time i load any world five minutes into it there are fatal freezings and eventually it just stays frozen it has been like this for a while and even if I create a new work it does nothing. Also another thing i have encountered was a glitch where you can't update a market place world and it says that you don't have enough space which I did or it will do nothing when I try to update it. A fix i have found was to delete the map from your data and redownload it which won't always work.