Rather, it doesn't close, it just freezes. It just happened for the second time.
I've checked my internet connection, and nothing changed. It just suddenly decides that there's no internet connection or something. No "lag" sign shows up. The cursor just stops moving.
Is there anything that might be causing this? Has anyone else had the same problem? It's amazing how errors seem to happen to Blockland more than any other game I play on my computer.