This version of <name> already has a label: overwrite?

Any version of a VSS file or project can have a label, which is used to identify that version. This error has the following cause and solution:

• One version of a file or project cannot have more than one label. Therefore, when you attempt to label a version that already has a label, VSS displays this message.

  Click Yes to apply the new label and replace the old label. Click No to cancel the action and leave the old label in place.