Texture Error - not 250x250

[SkinkFargle]

I'm trying to add some new warpaint to a race via the CK, but when I attempt to load it I get an error telling me that the texture is not 250x250.

 

When I load it anyway, all it displays in the preview is a mess of lines covering the character's face.

 

I attempted to edit the textures themselves to reduce their size, but there's multiple layers and I'm not sure how to resize it all properly.

 

Does anybody know how to properly resize textures? I won't go into it too much, but my GIMP didn't cooperate with my attempts to resize these textures.

 

Has anybody encountered something similar?

 

 

The error I receive is below:

 

FACEGEN: Tint mask texture 'Textures\actors\character\characterassets\tintmasks\"TheFile".dds' is not the correct expected dimensions of 256x256. Please resize the texture to match those dimensions.

 

And here's what it looks like when I load anyway: