This version of <File or Project> already has a label. Overwrite with new label?

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; the old label will remain.