I don’t know exactly where to post this, but I’ve been making some civil war uniforms and I’ve been able to upload the infantry and artillery uniforms but is says the cavalry ones “aren’t an image” when it clearly states it’s a .PNG file.
It states “Failed to create image: Upload failed. Make sure what you’re uploading is an image.”
What are the dimensions of the uniforms you’re trying to upload? Typically this error occurs, in my own experience, when the image isn’t the correct size. If you happened to use a thumbnail instead of an actual uniform design, the dimensions will be 420x420 which is an invalid clothing image size.