I don't know how to get the logs, because my game doesn't crash, I think its happening because i don't have the mod-list.json file. Look at the red text in the bottom left corner. Its a little hard to see.
Basically when I Tried to craft and item nothing happened. So i turned on cheat mode, and it said; the item lucraftcore:hammer does not exist. So I tried a different mod and it gave my the same thing.