I think this is what you are looking for, Crashed a few times when opening, have deleted and reinstalled already EDIT:
Looks like the Mojang text2 speech function is tripping you up. If it will load the pack you can use ctrl-b to turn the feature off. Now if it crashes before you even get to the Revelation title screen I'd try deleting the pack and reinstalling it as that is a default option in 1.12 so it may just have had a hiccup when installing the pack.
I tried deleting and reinstalling again, still crashed before reaching the title screen. Crashed at the same time as before, just before title screen should load
Might help, have you tried switching launchers? Either to MyM Launcher or to another Launcher such as Twitch? Let us know if this helps!