Call to a member function get_template_part() on null

[jeking]

Zen Cart 1.5.5d
PHP 5.6

The customer is reporting customers are having trouble checking out. Either time out errors or the site just spins. I cannot duplicate the issue, but I see this in the error logs. I don't find any reference in the forums. I don't suspect it's related to checkout, since I can place an order and not trigger any error. In browsing the site, I cannot trigger this error either.

PHP Fatal error: Call to a member function get_template_part() on null in /home/SITENAME/public_html/index.php on line 29

Line 29 is:
$directory_array = $template->get_template_part($code_page_directory, '/^header_php/');

[DrByte]

If calling "$template->get_template_part()" returns an error saying "Call to a member function get_template_part() on null",
that means that the $template variable has either not been defined yet or has been unset() (ie: removed) or set to blank (null).
This could happen if the auto-loader infrastructure doesn't load the template components (do you have new/altered code in includes/auto_loaders or /includes/init_includes directories?) due to having custom loading scripts or failures to load the usual scripts.
Or it could be that some code you've added is resetting the $template variable to something other than the object it is expected to be.

[jeking]

If calling "$template->get_template_part()" returns an error saying "Call to a member function get_template_part() on null",
that means that the $template variable has either not been defined yet or has been unset() (ie: removed) or set to blank (null).
This could happen if the auto-loader infrastructure doesn't load the template components (do you have new/altered code in includes/auto_loaders or /includes/init_includes directories?) due to having custom loading scripts or failures to load the usual scripts.
Or it could be that some code you've added is resetting the $template variable to something other than the object it is expected to be.

Thank you for the reply. It's an odd ball but I appreciate the input. Should I find any solution or specific cause, I will post back.

[DrByte]

Might be worth checking the IP address via the logs ... in case it's initiated by something like a SE spider, or some nefarious bad actor.