I had to disable Smush Pro because of this error:
Notice: Undefined index: accessible_colors in /home/academic/www/www/wp-content/plugins/wp-smush-pro/core/class-settings.php on line 274
Notice: Undefined index: usage in /home/academic/www/www/wp-content/plugins/wp-smush-pro/core/class-settings.php on line 275
Notice: Undefined index: keep_data in /home/academic/www/www/wp-content/plugins/wp-smush-pro/core/class-settings.php on line 276
Warning: Cannot modify header information – headers already sent by (output started at /home/academic/www/www/wp-content/plugins/wp-smush-pro/core/class-settings.php:274) in /home/academic/www/www/wp-admin/includes/misc.php on line 1196
