This keeps on happening to me, and when I try to reload my singleplayer universe, all the blocks disappear. Which is a shame, because I had a really nice ship I was building.
Specs, if they will help: (probably won't)
16 Gb RAM
i7 6700HQ @ 2.6 gHz
GTX 960M
EDIT: Picture
Specs, if they will help: (probably won't)
16 Gb RAM
i7 6700HQ @ 2.6 gHz
GTX 960M
EDIT: Picture