Comment 6 for bug 1678391

Hello, I think we can try setting the PPA (repository where the package lives) manually. The packages are specific for each version of Ubuntu and the purchases you made are for 14.04 packages, so please try on this version only.

To get a list of your package purchases, or subscriptions, go to https://software-center.ubuntu.com/subscriptions/. For each package, click on the link provided and you'll get to a page that says "Deb line for YOUR PACKAGE NAME for Ubuntu 14.04:". Below that text, there's a long line beginning with deb, similar to this (this is just an example, don't use this one):

deb https://roadmr:<email address hidden>/commercial-ppa-uploaders/some-name/ubuntu trusty main

Open a terminal, then type this to open a new text file:

sudo gedit /etc/apt/sources.list.d/purchases.list

Copy the "deb" line from the web page into this file (ensure it's only one line for each package), then save and close the file.

Next, open a terminal and run this:

sudo apt-get update

Next, run

sudo apt-get install youtubemusicdownloader
sudo apt-get install ultimate-media-downloader

to install the software.

I adapted those instructions from here, just for reference:

https://help.ubuntu.com/community/Pay/FAQs/Manual_Install

Also, as for the explanation: this appears to have happened because Ubuntu Software Center can only automatically set up the repository if you're using stock Ubuntu with the default desktop, not one of the variants like Ubuntu Studio.

Please let me know if you run into any issues with this procedure.