Entity:node context is required and not present

I was building a page using Page Manager and placing a Quick Tabs block in one of the page regions. When I tried to view the page I encountered an error in my log: "Uncaught PHP Exception Drupal\\Component\\Plugin\\Exception\\ContextException: "The 'entity:node' context is required and not present." at /[webroot]/core/lib/Drupal/Core/Plugin/Context/Context.php line 71, referer: http://[mywebsite]/admin/structure/page_manager"

When I remove the Quick Tabs block from the region in Page Manager the site appears normally again.

I did not try the -dev version because it has the same date as the alpha1 version I'm using.