Admin Page Framework registers a 'current_screen' action handler that's invoked via php's __call magic method rather than by being defined in the class. But Query Monitor's Hooks and Actions display assumes the action handler is actually defined, and shows an error if it is not.

Thanks to Klynt Maston for this report.

See also https://wordpress.org/support/topic/hooks-actions-hooks-invoked-with-__call-incorrectly-flagged-as-missing/