Hi there,
I'm sorry that you ran into trouble with this. The foundry that owns Rooney Sans asked that it be retired from the subscription font library.
Your client likely created their web project before that change. Adobe continues to serve retired fonts to any published projects, but the fonts can't be added to any new projects. There's more information on font retirement in this page:
https://helpx.adobe.com/fonts/using/retired-fonts.html
If you'd like to use Rooney Sans on a new project, you would need to purchase a font license for it. You can buy that license from our website to add it to your Adobe account (permanently) or you can license the fonts from the designer directly at https://www.janfromm.de/.
I hope that this helps; let me know if you have any other questions.
-- liz