The cause of this error in Magento 2 is missing php extension imagick or fileinfo both should be installed on the server
you can check if they are installed by creating new file in your Magento 2 root directory/pub you can name it info.php
and add this to the file
<?php phpinfo();
and access it from https://yourdomain.com/info.php
if you can’t find these extensions here
you have to install them
use these commands in your server to install them change php8.3 to your php running version these commands works in ubuntu OS
sudo apt update sudo apt install php-imagick sudo apt install php8.3-fileinfo