I had this error after a Windows upgrade:

 - drupal/core[8.8.0-alpha1, ..., 8.9.x-dev, 9.0.0-alpha1, ..., 9.5.x-dev] require ext-gd * -> it is missing from your system. Install or enable PHP's gd extension.

Solution

Open your php.ini and uncomment this line:

;extension=php_gd2.dll

 

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