Upgrade from 3.0.2.0 to 4.0.2.3 - files not found

OK - one last try to do this upgrade - I know - forget it and do an new install but it's getting close !

The upgrade completes - says its ok but it isn't and get an HTTP 500 error when I load the site. Get a couple of errors where it can't find the files and when I look in the debugger as follows:

index.php:45
GET http://localhost/opencart-website/publi ... nstall.css net::ERR_FAILED

VM17:1
GET http://mywebsite.com/cdn-cgi/challenge- ... sd/main.js net::ERR_ABORTED 404 (Not Found)

Not sure where these files are supposed to be as these folders don't appear anywhere on the site that I can see which is probably why they can't load.

Am I missing something or is this just and error in the script ?

Thanks

Using the upgrade functionality will almost always fail. It's better to do a fresh installation of your new OpenCart and then use the free Export/Import tool to copy over your product data. See also our FAQ on this.

Those errors are just missing files and would not cause a 500 error. They may not even be related to OpenCart. You need to check your PHP or server error log as well as the OpenCart one.

It seems they are causing by some 3rd party module. If you like we can check it on your website and fix.