Themes not functioning; only shows black

Hi MDT_DEBUT,

Welcome to the Roku Community!

Thanks for letting us know about this issue with the themes on your Roku TV. We're happy to help.

Please try to restart your Roku TV by following the steps below:

1. Press the Home button on your Roku remote. 
2. Scroll and select Settings.
3. Select System.
4. Select Power. If you do not see a Power submenu, skip to the next step.
5. Select System restart.

In addition to selecting a theme pack, you can further personalize your Roku device by:

• Changing the screensaver
• Setting the name and location of your Roku device
• Changing the format of the clock
• Hiding or showing shortcuts
• Blocking content using parental controls

Hope you'll find this info useful. Let us know in case you still have any questions.

Kind regards,
John