Dear Sir or Madam,
I don't know if this will help you or not but my screen savers are working once again.
1. make sure the ur smart tv, roku and screen savers are up-to-date in regard to software. Highlighting a screen saver and taping the * on the remote invokes a context menu where individual screen savers can be updated.
2. shut everything down i.e. tv (unplug it), roku (unplug it) , modem (unplug it).
3. If the roku has a micro card remove it and do not reinstall it.
4. Bring everything back up in this order: modem (wait until it reconnects to the internet), the tv, then the roku.
After the roku reconnects, try the screen saver.