I... Am not really sure what the hell happened. I just updated RFTools and Deep Resonance with everything that's needed for them, and now I can't load the world I play in, the game simply crashes.

Crash-log:
http://pastebin.com/XSADTXSu

Modlist:
https://dl.dropboxusercontent.com/u/77108893/Crash%20Reports/%D0%A1%D0%BA%D1%80%D0%B8%D0%BD%D1%88%D0%BE%D1%82%202015-10-29%2016.17.17.png

Could you provide the entire log? Maybe there is more information there

Here it is. It's the latest client one.
https://dl.dropboxusercontent.com/u/77108893/Crash%20Reports/World-crash.log

I see several problems in that log not related to RFTools. Like for example:

[16:14:46] [Server thread/ERROR] [FML/]: Exception caught during firing event cpw.mods.fml.common.gameevent.PlayerEvent$PlayerLoggedInEvent@1ffc1886:
java.lang.NullPointerException
at com.pahimar.ee3.exchange.EnergyValueRegistry.serialize(EnergyValueRegistry.java:804) ~[EnergyValueRegistry.class:?]
at com.pahimar.ee3.exchange.EnergyValueRegistry.serialize(EnergyValueRegistry.java:27) ~[EnergyValueRegistry.class:?]

Not sure what is going on though. I see nothing in that log indicating anything from RFTools or Deep Resonance though.

Well, the only reason I posted it to here is because I updated RFTools and Deep Resonance, and only after that it started happening. Could it be because of a wrong Forge version or something?

I don't see why. I develop with a very old version of Forge and in my own On The Edge modpack I have a very recent version and I don't have this problem... No idea really

Welp, updated Forge, nothing, but it said that there was some conflict with MineChem. Removed MineChem - still crashing. I guess the game doesn't want me to use the newest RFTools and Deep Resonance toys.
Gonna downgrade to an older version, see what happens.

It is most likely some conflict with a mod or so but it will be hard finding out what mod

@McJty The stacktrace you found is a known bug in EE3s dynEMC system and can temporarily be fixed by switching from pre calculated to post calculated values (don't ask me how).

Why does this only trigger when RFTools/DR is updated then? That's strange

Welp, it seems like there's something wrong with the world, not with any of the mods. Created a new world - it works. Tried to load the old world again - CRASH. Still don't know what mod's the culprit. Tried to remove ChromatiCraft, but it's useless because I'm literally living in a biome that it adds, and so the world gets corrupted.

Still got to try the old versions of DP and RFTools.

My guess is that some item IDs might have changed.

@DestinyPlayer item IDs are different between worlds. Try out what I wrote before, if you can figure out how to do it.

Nope, can neither figure out how to switch EE3 nor downgrade. The world's bust, completely and totally, downgrade fixes nothing.

@DestinyPlayer, if world is corrupted - that's sad, but for the future: don't forget to backup world often, especially before mod adding/update (better also with config folder).

Yeah. But it still turned out for the great, because it gave me a reason to build something pretty with stuff that I had in the old world while rebuilding in the new one, and not remain in the organically grown mess that I was.

I've managed to bring the world back (kinda) by removing everything about EE3 from it. Only kinda, because something still glitched out and it was lagging way more than it used to.