Having an issue with a custom character

[JoelMatthews]

So I've had this character mod for a very long time now, and I play as him a lot. But just after recent updates to the game, every time I try to select him to play as him, the game immediately crashes. I checked the log file...

../mods/Character/images/saveslot_portraits/character.tex is 120x104 but compressed textures must have power of 2 dimensions.
../mods/Character/images/selectscreen_portraits/character.tex is 188x284 but compressed textures must have power of 2 dimensions.
../mods/Character/images/selectscreen_portraits/character_silho.tex is 188x284 but compressed textures must have power of 2 dimensions.
../mods/Character/bigportraits/character.tex is 560x720 but compressed textures must have power of 2 dimensions.

... I'm not exactly sure what this means. It never gave me this error before. He always seemed to work fine before this! I would appreciate any and all help I could get regarding this issue.

Some possibly related notes: This happened when I tried to use Reign of Giants. Not sure if it does it for vanilla or SW. I'm also using a game controller and not a mouse. I'll update this when I experiment with these variables.

[Mobbstar]

On some systems, this "error" causes black boxes. Try to change the portraits' height and width to a power of two, whereas the two dimensions don't have to be the same length. e.g. 128x128, 256x512;

[JoelMatthews]

Thank you for the help! It, uh... it still crashed, for some reason. I went and resized everything, and I'm still getting the same error.

../mods/Character/images/saveslot_portraits/character.tex is 208x104 but compressed textures must have power of 2 dimensions.
../mods/Character/images/selectscreen_portraits/character.tex is 188x376 but compressed textures must have power of 2 dimensions.
../mods/Character/images/selectscreen_portraits/character_silho.tex is 188x376 but compressed textures must have power of 2 dimensions.
../mods/Character/bigportraits/character.tex is 360x720 but compressed textures must have power of 2 dimensions.

[Mobbstar]

Those are not powers of two. Powers of two are 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, etc.

By the way, this shouldn't crash your game at all. Are you sure there isn't a real error?

[JoelMatthews]

Oh, oops. Sorry, I had a silly moment! I'll try that too in a moment and update you.

And if there is, it's not telling me. It doesn't crash the game upon startup, just when I go to the character selection screen and scroll to where his face would be.