Ok if you’re confused then let me tell you again. Do not use the same keyword like events in theme option & page name. If you use the same slug as page & single post it’ll not work. You should create a page with different name then events then you’ll be able to set images & other things. The warning is showing because of the slug. If you’re using events as playbit_events slug the the main page should be named differently instead of events. Check the screenshot: http://prntscr.com/mjdt2z
Whatever you write as single page slug name you can’t use that name as a page name. You need to use a different name & permalink for pages. Hope this time you can understand what I’m trying to say. Thanks.