404 Error When Adding Repo to Install Manaually - Ubuntu Server 16.04

I keep on getting a 404 Error: Not found when trying to manually install OwnCloud on Ubuntu Server 16.04. I am using the exact instructions found here: https://download.owncloud.org/download/repositories/stable/owncloud/

I am using Apache2, PHP7, MySQL as my lamp stack.

You have a typo in your used URL as you're trying to download a "release.key" instead of the correct "Release.key".

To avoid such typos use copy'n'paste instead of manually typing URLs.