I think this is the key part of that page: "we don't recommend this."
I wasn't aware of the possibility and I've never tried it, so I'm not sure what might cause that. Server 500 errors are a real pain to diagnose.
There are some ideas here:
http://bobsguides.com/modx-installation-faq.html.
If probably would have been wise to disable or uninstall all plugins and snippets before doing the upgrade.
A good first step would be to delete all the files in the core/cache directory and clear your browser cache and cookies.
It's possible that some files did not overwrite existing files when you installed the Revo files (you did install the Revo core, manager, and connectors directories, right?).
Check the file core/config.config.inc.php and make sure the paths are correct.
Another thing to try would be to go into PhpMyAdmin (modx_system_settings table), turn FURLs off, then rename .htaccess to something else.
One more option would be to edit the modx_site_plugins table and disable all plugins (set the disabled field to 1).
Finally, you could edit the modx_site_content table and disable all snippets by putting a space between the opening brackets (except the *content tags).Then do the same in the chunks table (modx_site_htmlsnippets) and maybe the templates table (modx_site_templates).
If that works, you could re-enable the plugins and snippets one-by-one to see which one(s) are causing trouble.
[ed. note: BobRay last edited this post 14 years, 11 months ago.]