Creating a layout with Page Manager
Go to all recommended versions.

I was using different/more recent dev/alpha/beta versions of certain modules, but when I went to the recommended versions of...


panels (8.x-3.0-beta4)
page_manager (8.x-1.0-alpha23)
layout_plugin (8.x-1.0-alpha22)


... everything seemed to work okay. This was as of 7-6-2016