everytime i kill a new mob or if i morph into the mob it crashes my world and i have 0 idea why but this is a common bug
log file
https://pastebin.com/81PYyaCP

They do work together if you use optifine 1.7.10 version D6

but you cant even use shaders then

This issue is being closed as a purge of issues due to the Morph rewrite to 1.12.2 finally being released. Support for the 1.7.10 version has long been dropped and focus has shifted to the 1.12.2 version of the mod instead.

same thing happend to me :C

morph mod and Optifine don't work together

They do work together if you use optifine 1.7.10 version D6