Ok I post this crash here too because I think that TechReborn has a link with this crash. I get a serious crash when I try to launch minecraft with the last 1.9 version of Inventory Tweaks, TechReborn and Quark.
http://pastebin.com/U3mHZgSa

I noticed that when I create a new word, I get these errors. It doesn't make the game to crash, but I think it's the reason of why Inventory Tweaks crashes when it's installed. It seems that Quark and TechReborn add broken recipes.
http://pastebin.com/6bLwa8ga

In final I get a crash when I go in the command control when I'm playing into a word, but not when I'm in the menu, and I think that it's linked to the same problem.
http://pastebin.com/FALUi14a

I think that all these errors are linked. I informed the owners of Quark and Inventory Tweaks too. You should take contacts with them. I created an issue in the Quark github too.
VazkiiMods/Quark#28

Can someone point me to the inv tweeks dev?

I can't find it on Github, but here is the CurseForge page. http://minecraft.curseforge.com/projects/inventory-tweaks

I believe this is the relevant issue: Inventory-Tweaks/inventory-tweaks#342

Yeah this crash has been reported many times to the Inventory Tweaks owner. But it seems that nobody had made the link with the broken recipes of TechReborn and Quark.

If you read what he has said in the issue, its not an issue with TechReborn and he is waiting for the next version of modded minecraft. Dupe of #545 and #531 .

Turns out there is a PR to fix this: Inventory-Tweaks/inventory-tweaks#347