After a fresh install: Fatal Error: Class ACP either does not exist!

[Zayin]

So you were right about mod_rewrite. I found an article which led me to put this in to my .htaccess file in the admincp directory:

#Fix Rewrite
Options -Multiviews

Then, as soon as I clicked a tab in the acp, I got the original error from LotusRising's first post, for each link, as well as getting 403 forbidden when I entered the admin control panel. So after milling around for a while, trying different things, I chmod'd the whole admincp folder to be executable (755). This allowed me access to the admin control panel, but it was still giving me the original error above for each tab I accessed. So I made the whole classes folder and all its files 755 as well, and that fixed my problem! Now I have full access to mysidia!

Thanks