defender gives php warning on all plugins, can we solve that?

I am trying to speed up the mastersnetwerk site, checking everything with query monitor and see many warnings coming from defender when I activate it:

include(WP_Hummingbird.php): failed to open stream: No such file or directory
include(): Failed opening 'WP_Hummingbird.php' for inclusion (include_path='.:disappointed:usr/local/php70/lib/php')