Server start-up and save problems

So when I create a new world and let's say my last one , everything was going well , И was around day 300 and all of a sudden when I wanted to log in again my server was not even existing ... Or in other situations it's gonna pop failed to start dedicated server warning ... I'm kind of curious what could be the sourse of these problems becаuse they are kind of letting me down on this game , like grinding for nothing at the end : ) ( I have pretty damn low storage at my Disk Drive :C , around 2 GB , only think i could think of ). Have reinstalled the game , that doesn't help as well.