I tried changing graphics options and set everything to lowest values. I still got a crash. however, when I opened the world in 6.14.01 and looked up at the sky, then exited and loaded the same world in 6.14.02, it didn’t crash.
When switching versions (both ways), minecraft warns me about missing blocks that are being deleted. Maybe the crash is related to some blocks being added/removed by the 6.14.02? They would have to be part of worldgen I guess, since I don’t have NEI in the testing world.
Update: with render range set to minimum (2), I am now able to identify a specific area where the crash happens, as I approach the entrance to an underground cave.
I wonder, is there some tool like a debugger that could help me find out which block causes this?
Could it be one of these?

