This text represents a shortcut menu command in the Task Pane that has no link to an AutoCAD Map 3D command. For example, some topology commands that you choose from the shortcut menu in the Task Pane do not have corresponding AutoCAD Map 3D commands.
If you right-click in the drawing after completing such an action, you see "Repeat MAPWSACTION" in the menu. If you click this item, nothing will happen, by design. Likewise, if you right-click the command line, you see MAPWSACTION as one of the Recent Commands, but clicking on it will do nothing. The action that MAPWSACTION represents is not repeatable by typing MAPWSACTION on the command line. You must repeat the action from the Task Pane.
You cannot undo this operation using the UNDO command.