blockland is saved in two different places in your computer, for me it is
1. documents
2. local disk
documents should only have add-ons, saves , config, screen shots, base, etc.
and local disk should only have the program in it.
for you it might not be in those two places but check to see if you have the program in the same folder as your saves, the same thing happened to me not to long ago and that was the problem i was having -hope this helps.