Trouble posting header on subdomain site WP

I have no problem uploading the image and had no trouble installing the theme, which is the same Platform theme I am using under my domain, but my header will not show up after I hit save. It says can’t find what your looking for… Any Ideas https://www.webhostingreviewinnovations.com (domain)
https://www.webhostingreviewinnovations.com/blog (sub-domain)Thanks