When I have any USPS shipping method enabled, all customers (us and international) get an Error 500 when they click continue to get to their shipping options. I can't say that it happens all the time but usually.
I am using 4.2.2 and tried implementing the fix from this posting but no luck. I have opened a ticket with support but I can't wait till next week to have this resolved. Anyone have any ideas on what I should be looking for?
Look at the error log in the CS-Cart root directory. That should tell you what script and line is causing the error.
Actually, you might have to go further up the food chain to find the issue. The error_log file in your document root is a PHP file. But the 500 error comes from Apache.
Odds are it's an ownership/permissions issue related to your site. But your Apache error_log (usually in /var/log/httpd/error_log but could be in another location depending on your server) will identify the problem. It's possible that your access_log MIGHT show the problem, but unlikely.
The most common cause of a 500 error is directory/file permissions being too liberal. I.e. 777 should be 755 and 666 should be 644 for directories/files. Sometimes ownerships can also come into play. Generally for cpanel systems, the owner/group should match the cpanel username for all directories and files within the document root. However, the document root itself (I.e. public_html directory) is normally owned by the cpanel username, but the group is usually 'nobody'. Enforcement of these permissions are generally implementation specific.
Thanks to you both for your help. The script was stopping at the point in usps.php where CS Cart made their fix but there was not much to go on after that. I followed the suggestion about permissions and decided to run the chmod required per the install instructions. Since then I have not gotten the Error 500. So hopeully this is resolved. Thanks again.