I can only get into any world with deleting the Thermal Foundation / Expansion dense ores (I mean removing from the config). It has to do something with Thaumcraft as I saw.

Log file

Thanks for the help!

This thread is pretty old but I was wondering if someone figure out this problem. I'm having the same issue.

I found where the problem starts;

[21:48:22] [Server thread/ERROR] [FML/]: The following problems were captured during this phase
[21:48:22] [Server thread/ERROR] [FML/]: Caught exception from denseores

It's occurring approx 85% down the file, but wouldn't have a clue why.