Image upload is not working

[EmanDS]

Hello,
When uploading images I keep getting an Error Unknown error.

The Google Chrome console shows VM758:1 POST https://longwycreatif.fr/nosartisans/public/admin/blog/posts/upload/1 500

and the Laravel error log shows this:

[2022-08-29 13:45:09] local.ERROR: Trying to access array offset on value of type null {"userId":1,"email":"[email protected]","exception":"[object] (ErrorException(code: 0): Trying to access array offset on value of type null at /var/www/vhosts/longwycreatif.fr/httpdocs/nosartisans/app/Libraries/UploadHandler.php:368)

Any idea how to fix that ?

Best regards,
Emmanuel