Error: Cannot have multiple items selected in a DropDownList

Receiving this error when trying to select an item in an ASP.NET dropdownlist as below:

Dropdownlist1.items.FindByValue(“1”).Selected = True

To Solve this, just call the ClearSelected method before selecting the item:

Dropdownlist1.ClearSelection()
Dropdownlist1.items.FindByValue(“1”).Selected = True