I added \"cviebrock/image-validator\": \"1.0.*\" to require section of composer.json. After, I ran composer update
I Solved It With composer dump-autoload and then composer update
After that it works
But if you encounter more issue try to
Delete the vendor folder or just rename it fo backup puporse incase it fails like mv vendor ve then
Delete composer.lock
Run the command composer clearcache (or clear-cache) Run composer install
Your good to go.