If You happen to be an inquisitive person and work with SharePoint, You are in the right place.

Or maybe not sometimes... I was on the way to set up a test system for a client, which needed an empty Site Collection for the Solutions to be installed. So I created a Web-Application via Central Administration and a root WebSite-Collection with default Publishing Template.

As You will probably know it creates the Site Collection with an existing SubWebSite. So I deleted the Sub and saved the navigation again so as to refresh it.

Then a link in the Site Settings caught my eye: "Delete this WebSite".

Shouldn't have done that XD

The big Problem thereafter was: No ApplicationPage in Central Administration that had anything to do with Web-Sites or -Applications would work due to an uncaught NullReferenceException by Microsoft...

The only thing that helped: Good ole PowerShell:

Remove-SPWebApplication -identity http:// -Confirm

There You go again. Now the Central Admin Pages were accessible again. I love SharePoint...