Re: XAMPP Testing Question
It could be failing for any number of reasons, all of which are a result of a failure to access a required resource. That could be sending an email, it could be talking to an external server for another reason, it could be a lot of things. Especially problematic on non-live "test" servers since they're often not adequately equipped to do full website operations. It could also be a PHP error caused by a syntax error in one of your customizations or a badly installed addon or a poorly-written addon.
Related FAQ article: https://www.zen-cart.com/tutorials/index.php?article=82
Re: XAMPP Testing Question
I found the debug file that was talked about in the link you posted. Looks like it was a time out error. Here it is:
error: Maximum execution time of 30 seconds exceeded in C:\xampp\htdocs\zen\includes\classes\http_client.php on line 338
This is what line 338 looks like:
$this->replyString = trim(fgets($this->socket, 1024));
I haven't touched this file. Do you think I should just upload my site to my hosting server and see if I have the same problem?
Re: XAMPP Testing Question
That suggests that it's having trouble making an external communications attempt, and your local XAMPP server or your ISP are blocking the port/communications from taking place adequately.
So, yes, a proper test would be performed by loading the site to a properly hosted website.