Not related to this but something I was wondering, when I regenerated the htaccess for rewriting urls, it changed this line
RewriteRule \.(js|css|jpeg|jpg|gif|png|ico|map)(\?|$) /404error.php [L,NC]
to
RewriteRule \.(js|css|jpeg|jpg|gif|png|ico|map|webp)(\?|$) /404error.php [L,NC]
If I didn't regenerate the htaccess I wouldn't have known, so just wondering is this a recommended change