When you add an if statement on the designer, true and false branches are shown. But when you add something in the false branch the code is added to the wrong place of the code. In this stage, an Insert Else command is absent on the 3dot menu.
The following video shows what happens.
When you clear the code in the wrong place the if statement tree returns the one-branch and the Insert Else command is added to the 3dot menu.
After you add the else branch everything goes well.