MAC vs Important business such as website platforms "issues"

Got this "Mac" system recently, and um... it's been a while but I noticed there's an unusual website platforms or templates that seems to be altered and ceasing our "uploading" ability thru the Mac system, if the important websites are running but requires photos to upload, but Mac system seems not to have a specific file or folder that is missing? May I ask how do we solve that pesky issue?