Quote Originally Posted by mzimmers View Post
What does this mean, exactly? I've noticed that some modules seem to be scanned by ZC when they're installed, which is a new one on me, as I'm accustomed to php files being interpreted on the fly. Is this what you're talking about?
There are several directories in Zen Cart that are auto loading, meaning that any file in them are "loaded" ...

So if I have a file called:
/includes/modules/shipping/usps.php

and another file called:
/includes/modules/shipping/usps-old.php

it would load both files ...

The problem is, both files contain the same code and causes the error as the file content can only be loaded once ...

I rename files to:
/includes/modules/shipping/usps.php_OLD

so that it is not a php file ...

NOTE: The better solution is to not leave backup files on the server ...