What red error message you are getting and what image format images your are uploading .
File requirements and types
Shopify accepts .jpg, .png, and .gif file types for images and all major video file types such as .mp4 and .mov. If you upload .svg image files, then they will be converted to .png. The best file type for product images, pages, and blog posts is .jpg. The best file type for logos, borders, and trims is .png.
You can’t upload video files when you’re on a trial membership.
Each file needs to be smaller than 20 MB to upload to Shopify.