Installing and upgrading help
Opcache is causing connection reset of "site administration" pages
BTW... if this is a 'production' Moodle (as opposed to development or testing) then you shouldn't be using xampp. It's not suitable.
what should by used in its place which is as simple and user friendly as xampp?
Operating system? Windows Server 2008 R2
PHP version? PHP Version 7.2.6
How was PHP installed? XAMPP
Moodle version? Moodle 3.4.3+ (Build: 20180706)
What is in the web server's error log? nothing, no errors.
(i mean there are no errors in the logs, of xampp, php, mysql, no errors documented)