Crash when launching game. Something to do with lava flow?

Pressed play to run game. Mojang logo appears on the game screen as usual. Doesn't make it to the home screen but brings up this error...

The game crashed whilst initializing game
The game crashed whilst initializing game
Error: byx: Unable to fit: minecraft:blocks/lava_flow - size: 32x32 - Maybe try a lowerresolution resourcepack?

I tried to load again and it crashed again but it didn't allow me to view the crash report