Error processing file

Hi :)!
First of all, thank you for your plugin.
I have a problem while trying to optimize my images. It’s a brand new WordPress with only 2 images. When I try to optimize them, I have theses messages : https://snag.gy/HqJT6m.jpg

I must say that I have changed the default /wp-content/ to /content/ (security reasons) by simply doing that : https://www.hongkiat.com/blog/renaming-wordpress-wp-content-folder/

I hope you can help me :)! Thank you in advance!
Cedric