Hello,
I found that cron was never run on my website. When I ran it via web interface, it reported following error message.
Request you to please help.
Fatal error: Uncaught Error: Call to a member function real_escape_string() on null in /home/u854544305/domains/examiumclasses.in/public_html/live/lib/dml/mysqli_native_moodle_database.php:1140 Stack trace: #0 /home/u854544305/domains/examiumclasses.in/public_html/live/lib/dml/mysqli_native_moodle_database.php(1269): mysqli_native_moodle_database->emulate_bound_params('SELECT RELEASE_...', Array) #1 /home/u854544305/domains/examiumclasses.in/public_html/live/lib/dml/moodle_database.php(1624): mysqli_native_moodle_database->get_records_sql('SELECT RELEASE_...', Array, 0, 0) #2 /home/u854544305/domains/examiumclasses.in/public_html/live/lib/classes/lock/mysql_lock_factory.php(158): moodle_database->get_record_sql('SELECT RELEASE_...', Array) #3 /home/u854544305/domains/examiumclasses.in/public_html/live/lib/classes/lock/lock.php(102): core\lock\mysql_lock_factory->release_lock(Object(core\lock\lock)) #4 /home/u854544305/domains/examiumclasses.in/public_html/live/lib/classes/lock/lock.php(116): core\lock\lock->release() #5 [ in /home/u854544305/domains/examiumclasses.in/public_html/live/lib/dml/mysqli_native_moodle_database.php on line 1140regards.