This issue usually happens when the file has not yet been unzipped.
If you have never worked with zipped files before, please check out our guides on how to unzip a zip file below
How to unzip files (Windows PC)
How to unzip files (Mac)
How to unzip files (iPhone/iPad)
How to unzip files (Android)
If you're certain the file has been unzipped you might have selected the wrong file type to upload. Cricut Design Space supports svg, jpg, png and dxf files.
(Note: jpg and png uploaded as a single layer generally used for Print Then Cut and dxf is not currently supported in Design Space for mobile devices).