Issue with Bed Texture

Hiya! I'm new to S4S as of last night. I decided to download and give it shot bc I wanted to make some more bed options with quilts, namely the quilt textures from the four-poster bed from Cats and Dogs. I've been playing with putting them on the Rustic Dream bed frame, but only the first three bed textures are showing up in the game. The other three are showing up, but where the bedding texture should be is an error texture (see below)

Here's a screenshot of S4S with the bed texture that's showing an error in-game:

To edit the texture photos, I've been importing them into Adobe Illustrator, then exporting as png files. it's mainly just to put the quilt texture on this particular sheet texture bc I like the clean white sheets as a backing for the quilts.

As I said, I'm brand to new to this, so I'm not sure where I'm going wrong. I would attach the package file, but I guess since this is my first post, it won't let me attach one yet lol.

Any help would be greatly appreciated! Thank you!