Quote from Captain_Chaos
Would you mind putting that crash report in [spoiler] tags? It's a bit long and cluttering up the thread.
I don't know what could have caused that. It sounds similar to a problem somebody else recently reported, but that was in Minecraft 1.5.2, which makes it double strange. I can't reproduce it, if I create a new map with WorldPainter 1.6.4 and load it in Minecraft 1.7.2 it just works. Could you send me a .world file which demonstrates the crash (please doublecheck that it does actually crash Minecraft when you export it)?
Sorry about the spoiler tags, it is fixed now
But anyway, I tried downgrading my minecraft to 1.6.4 and playing on the map, and it worked just fine. When I upgraded to 1.7.2 again, it still worked. The other worlds I made in WorldPainter still made me crash though. I think I am just going play my worlds in 1.6.4 first and then upgrade them to 1.7.2.