... and if it helps following is what I get in error logs:

[13-Jun-2019 16:09:29 UTC] PHP Fatal error: Uncaught Error: Call to a member function isMobile() on null in /home/mgs10000/public_html/includes/templates/responsive_classic/common/main_template_vars.php:32
Stack trace:
#0 /home/mgs10000/public_html/index.php(49): require()
#1 {main}
thrown in /home/mgs10000/public_html/includes/templates/responsive_classic/common/main_template_vars.php on line 32

[13-Jun-2019 16:09:29 UTC] Request URI: /index.php?main_page=sitemapxml&rebuild=yes&ping=yes, IP address: 73.107.135.155
--> PHP Fatal error: Uncaught Error: Call to a member function isMobile() on null in /home/mgs10000/public_html/includes/templates/responsive_classic/common/main_template_vars.php:32
Stack trace:
#0 /home/mgs10000/public_html/index.php(49): require()
#1 {main}
thrown in /home/mgs10000/public_html/includes/templates/responsive_classic/common/main_template_vars.php on line 32.