Yes I have about a million mods but removing TrashSlot seems to fix this crash that happens switching dimensions.

was going to the tardis dimension here.
http://hastebin.com/jusilefapo.1c

and heres a "fresh" instance with the same error on going to the nether.
http://hastebin.com/foragemizi.vhdl

also tested on a server, no crash server side but causes the client to crash.

neat mod 👍
mrammy

replicated it again in latest version leaving a modded dimension. seemed to work fine for the nether and end. Tested with Extra Utilities deep dark and last millennium.

heres the crash-log anyway seems identical http://hastebin.com/ivayofasez.vhdl