Plugin version: 3.0.1
When activating this plugin I got a "This plugin does not have a valid header."
This might only happen on certain server configurations. Some server set-ups are 'picky' about how the PHP tag is opened is my experience, and it will need a lowercase full opening to work properly.*
In auto-post-images.php in the plugin folder changing the uppercase PHP:
<?PHP /* Plugin Name: Auto Post Images (API)
to lowercase php:
<?php /* Plugin Name: Auto Post Images (API)