Trying to launch a custom pack and I get this error message

The game crashed whilst initializing game
Error: java.lang.NoClassDefFoundError: net/minecraft/client/renderer/entity/RenderSkeleton$1

Tried removing mods and launching till it worked and runs fine when I take Quark out but not sure why this is happening?

Crash log - https://pastebin.com/fC5QszYz

I am also having this issue.

Dupe of #449