Okay, so I have multiverse, and I have a world named Pixel Art, so that I can work on my pixel art, while my players play on my server. (My server's hosted from my computer, if that helps) But when I try to /mvtp Pixel Art it says "Sorry, I couldn't find player: Pixel" So I tried /mvtp Pixel_Art and it also didn't work. So I would appreciate any help that you guys can give me, thanks.
have you tried /mvtp <yourname> <worldname>? i'm unfamiliar with that mod, but it's looking for a player name. try giving it one.
Using spaces in map names has always been an issue, I simply wouldn't do it. Use MultiVerse alias to achieve that, so your folders are without spaces. Also, https://github.com/Multiverse/Multiverse-Core/wiki/Command-Reference#wiki-spacesnote