Never mind, I found out my .jar had become corrupted!I just had to download it again! Problem solved.
Where are those two files located? I can't seem to find them.
Still having the issue. It seems to happen more often, I realize, if I click the "Create World" button from the screen where one inputs seed, cheats, world type, etc.
@Cube I forced update and no change. The problem persists on all 3 world types.
@Kumasasa How do I update?
I could go for hours explaining it.