windows - c# system device location works off and on -

i have code should work location sensing, , work once , while lately without change code geopositionstatus equal nodata. location services on , worked few days ago , nothing has changed since. why isn't working now? advice? computer windows 10 , location device on.

    static geocoordinatewatcher _watcher;     /// <summary>     ///     /// main entry point application.     /// </summary>     [stathread]     static void main()     {         application.enablevisualstyles();         application.setcompatibletextrenderingdefault(false);         //application.run(new form1());         _watcher = new geocoordinatewatcher();         _watcher.statuschanged += watcher_statuschanged;         _watcher.positionchanged += geopositionchanged;          _watcher.start();         thread.sleep(500);         var coord = _watcher.position.location;     }      private static void watcher_statuschanged(object sender, geopositionstatuschangedeventargs e)     {         if (e.status == geopositionstatus.ready)         {             messagebox.show("watcher ready. first location: current location is: " +           _watcher.position.location.latitude + "/" +           _watcher.position.location.longitude + ".");         }     }      private static void geopositionchanged(object sender, geopositionchangedeventargs<geocoordinate> e)     {         messagebox.show("the current location is: " +             e.position.location.latitude + "/" +             e.position.location.longitude + ".");     }