OSClass 2.3.5 is the problem!
Manually create your MySQL database:
DBname: osclass
username: whatever
password: use a simple 11 character password
use the default oc_ as the prefix
If you have previously failed the installation just delete the config.php file (it will be recreated)
If you have copied all the files to your domain root just go your domain.xx or xxx or whatever in your browser and the installation will start.
If you have copied all the files to a sub-folder of your domain root just go your domain.xx or xxx or whatever (example:
http://domain.com/sub-folder) in your browser and the installation will start.
If you have everything copied to a sub-domain go to your sub-domain.domain.xx or xxx or whatever in your browser and the installation will start.
Copy your correct information into the database installation and if all goes well, after setting your location tou'll be able to set up your categories.
If the installation fails, open the config.php and see if the password was changed. If it was, just go to your database, change the password to something else that is simple and easy delete the config.php and start the installation again.
When you're successful it means that the OSClass installation approved the password you used.
This took me hours to figure out but then I'm a newbie!
Mac