I have installed a Launch-Distribution supported by the extension-manager > Get preconfigured distribution.
But page tree is empty, page "Launch it!" isn't shown.
If nothing can solve the bug, you can create the page "Launch it!" manually.
Create a page and call it "Launch it!"
Add a TypoScript template
[X] setup and
like in the illustration above.
Include the static templates
Launch  and
Launch  of your Launch-TYPO3-Distribution
Add the plugin "Launch it!"
Your page with the template record and the content element.
Visit your page in the frontend.