This will usually happen on first-time installs of Zen Cart to a webserver you haven't used Zen Cart on before, and especially on (but not limited to) Windows/IIS hosts.
If you have access to your server's errorlog data, you can confirm that this is the problem by viewing the logs. They will most likely tell you "Limit option not allowed here".
You have a couple options:
- PREFERRED: Ask your hosting company to add the "Limit" keyword to the AllowOverrides parameter of your domain's vhost configuration in their server's httpd.conf settings file.
This is your most secure option for Apache-based Webservers.
Windows IIS Webservers, this option is of no value. You'll have to use the following method instead:
- If they won't do that for you, you'll have to disable the security protections that the supplied .htaccess files would normally provide for you:
Simply use your FTP program to temporarily rename the /includes/.htaccess file to htaccess_OFF
Do the same for your /admin/includes/.htaccess file, since similar symptoms are likely occurring there as well.
After making this change, if your stylesheet loads properly (formatting appears more like you expected), then the settings in this .htaccess file will need to be altered for compatibility with your webhost, or you can choose to ignore their security benefits completely. The logic in the /includes/.htaccess and /admin/includes/.htaccess files basically just say "for all *.php files, don't allow them to be accessed via a browser directly". Your host should be able to help you secure those folders using other means if they're not willing to make the change suggested in option #1 above.