Help for Aimeos

I am meeting this error every time i try to upload a video for the header carousel How can I fix this.. am running Aimeos as a standalone so its not in nginx or Apache but probably using Apache I'm not sure I just run PHP artisan serves on the terminal in my Documents directory and I encounter this ...

I have read through the product package installation and I can't get a grasp of the actual media files from the site. I need some help with organization and changing the media files from the homepage to fit my suitable needs. And how can I also make changes to the header if possible? lts-aimeos pack...