Log Errors Produced When Site is Down For Maintenance

Zen Cart 1.5.6a
Database Patch Level: 1.5.6
PHP Version: 7.2.17 (Zend: 3.2.0)

<<modules>>
backup_mysql
encrypted_master_password
keep_cart
numinix-google-analytics
remember me
usu-3.0
Image Handler 5
SitemapXML

[26-Apr-2019 00:34:06 UTC] Request URI: /index.php?main_page=down_for_maintenance, IP address: 66.249.XX.XX
#1 require(/home/shrimps/public_html/includes/init_includes/init_sessions.php) called at [/home/shrimps/public_html/includes/autoload_func.php:48]
#2 require(/home/shrimps/public_html/includes/autoload_func.php) called at [/home/shrimps/public_html/includes/application_top.php:170]
#3 require(/home/shrimps/public_html/includes/application_top.php) called at [/home/shrimps/public_html/index.php:26]
--> PHP Warning: Use of undefined constant OFFICE_IP_TO_HOST_ADDRESS - assumed 'OFFICE_IP_TO_HOST_ADDRESS' (this will throw an Error in a future version of PHP) in /home/shrimps/public_html/includes/init_includes/init_sessions.php on line 112.

[26-Apr-2019 00:34:05 UTC] Request URI: /robots.txt, IP address: 66.249.XX.XX
#1 require(/home/shrimps/public_html/includes/init_includes/init_sessions.php) called at [/home/shrimps/public_html/includes/autoload_func.php:48]
#2 require(/home/shrimps/public_html/includes/autoload_func.php) called at [/home/shrimps/public_html/includes/application_top.php:170]
#3 require(/home/shrimps/public_html/includes/application_top.php) called at [/home/shrimps/public_html/index.php:26]
--> PHP Warning: Use of undefined constant OFFICE_IP_TO_HOST_ADDRESS - assumed 'OFFICE_IP_TO_HOST_ADDRESS' (this will throw an Error in a future version of PHP) in /home/shrimps/public_html/includes/init_includes/init_sessions.php on line 112.

[26-Apr-2019 00:08:36 UTC] Request URI: /, IP address: 68.206.XX.XX
#1 require(/home/shrimps/public_html/includes/init_includes/init_sessions.php) called at [/home/shrimps/public_html/includes/autoload_func.php:48]
#2 require(/home/shrimps/public_html/includes/autoload_func.php) called at [/home/shrimps/public_html/includes/application_top.php:170]
#3 require(/home/shrimps/public_html/includes/application_top.php) called at [/home/shrimps/public_html/index.php:26]
--> PHP Warning: Use of undefined constant OFFICE_IP_TO_HOST_ADDRESS - assumed 'OFFICE_IP_TO_HOST_ADDRESS' (this will throw an Error in a future version of PHP) in /home/shrimps/public_html/includes/init_includes/init_sessions.php on line 112.

[26-Apr-2019 00:08:32 UTC] Request URI: /favicon.ico, IP address: 68.206.XX.XX
#1 require(/home/shrimps/public_html/includes/init_includes/init_sessions.php) called at [/home/shrimps/public_html/includes/autoload_func.php:48]
#2 require(/home/shrimps/public_html/includes/autoload_func.php) called at [/home/shrimps/public_html/includes/application_top.php:170]
#3 require(/home/shrimps/public_html/includes/application_top.php) called at [/home/shrimps/public_html/index.php:26]
--> PHP Warning: Use of undefined constant OFFICE_IP_TO_HOST_ADDRESS - assumed 'OFFICE_IP_TO_HOST_ADDRESS' (this will throw an Error in a future version of PHP) in /home/shrimps/public_html/includes/init_includes/init_sessions.php on line 112.

This constant must be missing from your language files. You should have:

./languages/YOUR_LANGUAGE/email_extras.php:if (!defined('OFFICE_IP_TO_HOST_ADDRESS')) define('OFFICE_IP_TO_HOST_ADDRESS', 'OFF');

I don't know the reason I got it but that is in that file.... I have not seen this error yet more than once so I don't know what is going on... Thank you!

In the SitemapXML module there is a russian language included in that directory that doesn't have any defining files.... maybe that is what set it off? I deleted that directory so we will see.