How do I setup custom error pages?

To setup your custom error page, you will need to use a .htaccess file. Put the following line(s) in this text file:

ErrorDocument 404 /path_to/not_found_error_page.html
ErrorDocument 403 /path_to/forbidden_error_page.html
ErrorDocument 401 /path_to/authorization_error_page.html
ErrorDocument 500 /path_to/internal_server_error_page.html

Then upload this file to your mainwebsite_html directory.