deprecated function error
On dmaster go to Manage Events, then click on the leftmost icon on top right (blue in the included image).
Error that shows is:
Deprecated function: Non-static method CRM_Event_ICalendar::run() should not be called statically in CRM_Core_Invoke::runItem() (line 278 of /srv/buildkit/build/dmaster/web/sites/all/modules/civicrm/CRM/Core/Invoke.php).