XCode 9.4.1 (9F2000)

The following warning occurred in Storyborad on iOS.

~/ProjectName/ProjectName/Base.lproj/Main.storyboard:
Segues initiated directly from view controllers must have an identifier

Segies requires an ID when attaching to another View Controller as it is from the View Controller.

The warning disappears when Segue is selected and the Identifier is set from the Attirbute inspector.

“If you use Segue, you need an ID, so give it a name.”