Notice

File common.php

function ewww_image_optimizer_update_attachment_metadata..

Line 1418
if ( $log ) ...

Notice:
Notice: Undefined variable: log in ../wp-content/plugins/ewww-image-optimizer/common.php

Seems like the $log is not defined anywhere in that function.

https://ww.wp.xz.cn/plugins/ewww-image-optimizer/