pretty self-explanitory.

the textures seem to be randomly replaced. there are a few patterns I have spotted, such as mekanism and RFtools textures always replacing reeds.

I'm facing the exact same issue. I loaded a new world, and everything was working fine. Better Foliage's additional leaves weren't transparent, so I went into resource packs and loaded a few packs I left out for testing. When the game loaded again all textures were messed up. I tried reloading the world, and it didn't work. Restarted the game, the textures were still broken. The only thing I haven't tried is recreating the world, which I'll do right now.

I don't know if this is a mod compatibility issue or a standalone Better Foliage's issue. Hopefully, it'll be fixed soon.

Update: Re-creating the world seems to fix it. Removing the mod altogether fixes it too.

I have this on the Hypixel server. Going out of and into the game fixed it for me.

Modlist (WIP [I don't have the time])

Oak Logs:

Spruce Logs: