MayorRev

Ah, I think it may be Creative Core, actually. Biomes O Plenty and Carry On don't seem to affect the commands, and I can't use Ambient Sounds without Creative Core, so that must be the one causing it. Is there a way to configure Creative Core so it can use the default commands? I'd love to have ambient sounds but if there's no way to prevent this change, I guess there's not much I can do.

Yep, so it seems like one of my mods is doing it. Not sure which one, though.

I have a handful, yes. Here they are below. I also installed OptiFine as a separate installation to boot the game on, but I don't have much need for it.

I'm new to installing Forge, so I'm unfamiliar with the process of things. I noticed that I've been given a unique but unfamiliar set of commands for my singleplayer game. I was looking for the default commands and cheats but I can't seem to find them, and the game doesn't recognize things like /give or /summon. Can I change this? If so, how? Below is an image set of the commands I've been given.