http://pastebin.com/zR3XZvvF - I get this when fiddling with lighting updates around the void in Extra Utilities' Deep Dark dimension. I got this half a dozen times either picking lava source blocks up or allowing the flowing lava to pour into the void. I get the crash placing torches as well, at Y=3.

http://pastebin.com/LCuQ3Sc8 - I get this when doing the same thing in the Overworld. I busted a piece of bedrock and placed a torch down. It didn't immediately crash but when I busted the torch, crash.

http://pastebin.com/K6bDJMHq - .. and, the Nether. Just dug straight down in Creative and let the lava flow into the void.

I wasn't sure if this was something fixed in 1.3.4 (I'm still using 1.3.3 because broken sunlight) so please disregard if useless.

Yeah, 1.3.3 is still quite unstable, so I'm not completely surprised. Maybe I can spend some time here today.

i think this isnt revelant any more, caused by the lighting values being larger then 0-15 for the extended data

Update: Similar crash for 1.3.5 build 29 - http://pastebin.com/wRR3wXqj

Dug straight down, broke bedrock, placed Red colored glowstone near the hole, no crash. Placed lava, paused a few seconds, then crash.

A screen shot right before crash would be fantastic! (I'll look at this soon)

Sounds like an issue with the lava flowing out or near the edge of a world, and then the lighting engine dies on when lava is on the edge where bedrock used to be.

http://imgur.com/4h5bSsQ - oops, forgot to add this to GitHub. I tossed it and a whole gallery of pics in the MCF thread if interested. The bedrock hole is under the flowing lava (source block is to the left). This pic was taken maybe a second, or less, before crash.

That was fun! Same issue happens on lights at the TOP of the world... presumable the far x and z extremes of the world are also unstable.....

but we can ignore those for now :)

http://coloredlightscore.us.to:8080/job/ColoredLightsCore%20v1.7.10/30/