If you get error(500) , error(501) , error(503) , error(504) then you can assume that some of those php parameters are not working well as all 5xx errors are server generated error and nothing to do with Theme. Try to talk to your hosting about the error and ask them to set those parameters properly. Hosting companies always tend to shrug off any responsibility and would say that it’s the theme which is causing the issue. Radiant Themes framework is being used on over 10000 sites across different hosting network and across the world and in 99% cases we see buyers don’t face any problem at all.
If nothing works for you, then please get in touch with Support Team with your HOSTING access and permission to transfer demo designs via WP staging method. We’ll require temporary access (cPanel for example) of your hosting (NOT just FTP) to initiate WP Staging.
Demo Design IMPORT WON’T WORK on WordPress.com hosted site.