Not working properly while uploading webp images

[waqasy]

Hi again,

I've been testing this plugin. Everything works fine except uploading webp format. When uploaded through media_handle_sideload it generates following error.

[error] 6105#6105: *501 FastCGI sent in stderr: "PHP message: PHP Warning: Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/rj-webp-converter-master/includes/lib/class-rj-webp-converter-admin-main.php on line 70" while reading response header from upstream, client: xxx.255.5.96, server: example.com, request: "POST /wp-admin/async-upload.php HTTP/2.0", upstream: "fastcgi://unix:/run/php/php7.0-fpm.sock:", host: "example.com", referrer: "https://example.com/wp-admin/media-new.php"

And If I try uploading webp image from wp-admin > library. It uploads the image but then wordpress doesn't generates thumbnails. I think its Wordpress issue that its not generating thumbs. Because also by default Wordpress don't allow .webp uploads..