class.upload.php is a powerful and mature PHP class to manage uploaded files, and manipulate images in many ways. The script is available under a GPL license.
On your OS (LInux), the class uses FileInfo PECL extension to detect MIME type, and it detects application/encrypted, which is very generic, and dangerous to allow.
You may try to deactivate FileInfo in order to rely instead on Unix file command: deactivate the code using fileinfo in the class. Search for this line in the class:
You may try to deactivate FileInfo in order to rely instead on Unix file command: deactivate the code using fileinfo in the class. Search for this line in the class:
And replace it with