Thanks for posting here at the Roku Community, @Mestubby.
We're grateful to see your appreciation of the Aquatic Life screensaver on the Roku streaming platform. No worries. We're here to find you the best resolution to your concern.
May we first know what is your current OS version? You can check it through Settings > System > About. Furthermore, try to perform a system reboot on your Roku streaming device by navigating to your Home screen. Scroll up or down to select Settings > System > System restart. After doing so, try to install the screensaver again and press the star* button to add it to your channel lineup on your Home screen.
Let us know how it goes! We'll be anticipating your response.
Kind regards,
Carly
Carly Y.
Roku Community Moderator