For some reason, using multiconnect causes the OptiFine-modded Video Settings menu to display the names of its strings instead of its actual string content.

Even stranger is that if you open Video Settings from the title screen right after opening Minecraft, it's fine:

But after loading a singleplayer or multiplayer world, the Video Settings menu in-game or in the title screen are messed up until Minecraft is restarted.

Versions:
Fabric Loader 0.7.9+build.190-1.15.2
Minecraft 1.15.2
multiconnect 1.2.2
OptiFabric 1.0.0-beta8
OptiFine 1.15.2_HD_U_G1_pre13

Ugh, this is optifine breaking multiconnect, not multiconnect breaking optifine. Anyway, I'll see what I can do.

Ah yes, it was optifine doing stupid things again. I found a workaround though!