It looks like with the latest copy of Bricks-Child theme, the zip file was created without the containing “bricks-child” folder, which breaks installation.
Shown at the end of the video by opening the zip file and seeing that the contents are not contained in a bricks-child folder as they should be.
I’m unable to replicate the issue you’re facing with the missing bricks-child folder, could you please clear your cache & try downloading the child theme again?
You should try to upload the core bricks theme again as well, if you always encounter 404 when uploading a new plugin or theme, you should check your website htaccess or server rewrite rules.