Well.

Bit more of a trouble than I wish to deal with today, but apparently Mongrel has changed somewhat in the latest version and doesn't deliver content as HTML, instead delivering it as text/plain (source html).

If you are using Mongrel to deliver your Ruby Apps, and you're sure your versions of gems meet the requirements - take a look at the below to try.

Add this file in, restart your application - and hopefully away you go. Again there is a lot of read/take in when it comes to dealing with this issue - hopefully I'm saving you about 1.5 hours of research. Original Source for the Patch I've forked..

It's not nearly has hard when you know what the hell you're doing.  Oh by the way, that's not the case with me <_<  Find an installation guide elsewhere (or even adapt the actual installation guide from Redmine).  This guide is manually how to setup rewrite rules properly so you can use Redmine as ether a proper subdomain entry (redmine.yourdomain.com) or even slightly more tricky, as a subdomain entry (www.yourdomain.com/redmine).  Sadly cPanel htaccess rules generated from their interface ... suck.  Pretty badly >_>  No idea why.

MOVING ON.