I think I know what may be going on here.
How are you downloading this file exactly? Are you downloading it by navigating to the file URL in a web browser? Or are you downloading it to some other piece of software?
If so, please note that we do not provide file hosting services, and that we run a security system that means only web browsers can access content hosted with us:
The 800 bytes you’re seeing roughly matches the size of the HTML/JS content being returned for the browser validation challenge.
If this is the case, the solution is simple: don’t use our website hosting for file sharing. Please upload the files to a file or image sharing service instead.