All you should have to do to enable mod_rewrite is the a2enmod command and restarting the server, and the AllowOverride change. The AllowOverride change you posted about earlier in the apache2.conf file should be sufficient.
When you see that “mod_rewrite is not enabled” error page, it generally means one of three things:
- mod_rewrite isn’t enabled (this is what the
a2enmodcommand does) - The .htaccess file is missing or in the wrong place (it looks like it’s in the right place from what you posted earlier)
- The AllowOverride directive isn’t set to All (meaning the .htaccess file is being ignored. You can test to see if this is the case by adding some gibberish to the top of the .htaccess; it should cause an Internal Server Error if the file is actually being respected by the server).
There’s a way to just bypass this rewrite detection step but given the error you’re seeing at the root I doubt things would work properly if you did it.
Did you remove the RewriteEngine On block from the apache2.conf file?
This is getting a little far afield for the Omeka forums as we’re more in the realm of Ubuntu system administration.