c# - How can I debug an intermittent unhandled exception "Must disconnect specified child from current parent Visual"? -

i'm getting intermittent unhandledexception must disconnect specified child current parent visual before attaching new parent visual stacktrace references system.* , ms.* calls. looks datepicker left-mouse clicked, , trying toggle pop-up (i'm guessing calendar widget). there lots of datepickers in application. don't know 1 caused exception.

how can debug this?

unhandledexception: must disconnect specified child current parent visual before attaching new parent visual.     @ system.windows.media.visual.addvisualchild(visual child)     @ system.windows.documents.nonlogicaladornerdecorator.set_child(uielement value)     @ system.windows.controls.primitives.popup.createwindow(boolean asynccall)     @ system.windows.controls.primitives.popup.onisopenchanged(dependencyobject d, dependencypropertychangedeventargs e)     @ system.windows.dependencyobject.onpropertychanged(dependencypropertychangedeventargs e)     @ system.windows.frameworkelement.onpropertychanged(dependencypropertychangedeventargs e)     @ system.windows.dependencyobject.notifypropertychange(dependencypropertychangedeventargs args)     @ system.windows.dependencyobject.updateeffectivevalue(entryindex entryindex, dependencyproperty dp, propertymetadata metadata, effectivevalueentry oldentry, effectivevalueentry& newentry, boolean coercewithdeferredreference, boolean coercewithcurrentvalue, operationtype operationtype)     @ system.windows.dependencyobject.setvaluecommon(dependencyproperty dp, object value, propertymetadata metadata, boolean coercewithdeferredreference, boolean coercewithcurrentvalue, operationtype operationtype, boolean isinternal)     @ system.windows.dependencyobject.setvalue(dependencyproperty dp, object value)     @ system.windows.controls.datepicker.onisdropdownopenchanged(dependencyobject d, dependencypropertychangedeventargs e)     @ system.windows.dependencyobject.onpropertychanged(dependencypropertychangedeventargs e)     @ system.windows.frameworkelement.onpropertychanged(dependencypropertychangedeventargs e)     @ system.windows.dependencyobject.notifypropertychange(dependencypropertychangedeventargs args)     @ system.windows.dependencyobject.updateeffectivevalue(entryindex entryindex, dependencyproperty dp, propertymetadata metadata, effectivevalueentry oldentry, effectivevalueentry& newentry, boolean coercewithdeferredreference, boolean coercewithcurrentvalue, operationtype operationtype)     @ system.windows.dependencyobject.setvaluecommon(dependencyproperty dp, object value, propertymetadata metadata, boolean coercewithdeferredreference, boolean coercewithcurrentvalue, operationtype operationtype, boolean isinternal)     @ system.windows.dependencyobject.setcurrentvalueinternal(dependencyproperty dp, object value)     @ system.windows.controls.datepicker.togglepopup()     @ system.windows.controls.datepicker.dropdownbutton_click(object sender, routedeventargs e)     @ system.windows.routedeventhandlerinfo.invokehandler(object target, routedeventargs routedeventargs)     @ system.windows.eventroute.invokehandlersimpl(object source, routedeventargs args, boolean reraised)     @ system.windows.uielement.raiseeventimpl(dependencyobject sender, routedeventargs args)     @ system.windows.uielement.raiseevent(routedeventargs e)     @ system.windows.controls.primitives.buttonbase.onclick()     @ system.windows.controls.button.onclick()     @ system.windows.controls.primitives.buttonbase.onmouseleftbuttonup(mousebuttoneventargs e)     @ system.windows.uielement.onmouseleftbuttonupthunk(object sender, mousebuttoneventargs e)     @ system.windows.input.mousebuttoneventargs.invokeeventhandler(delegate generichandler, object generictarget)     @ system.windows.routedeventargs.invokehandler(delegate handler, object target)     @ system.windows.routedeventhandlerinfo.invokehandler(object target, routedeventargs routedeventargs)     @ system.windows.eventroute.invokehandlersimpl(object source, routedeventargs args, boolean reraised)     @ system.windows.uielement.reraiseeventas(dependencyobject sender, routedeventargs args, routedevent newevent)     @ system.windows.uielement.onmouseupthunk(object sender, mousebuttoneventargs e)     @ system.windows.input.mousebuttoneventargs.invokeeventhandler(delegate generichandler, object generictarget)     @ system.windows.routedeventargs.invokehandler(delegate handler, object target)     @ system.windows.routedeventhandlerinfo.invokehandler(object target, routedeventargs routedeventargs)     @ system.windows.eventroute.invokehandlersimpl(object source, routedeventargs args, boolean reraised)     @ system.windows.uielement.raiseeventimpl(dependencyobject sender, routedeventargs args)     @ system.windows.uielement.raisetrustedevent(routedeventargs args)     @ system.windows.uielement.raiseevent(routedeventargs args, boolean trusted)     @ system.windows.input.inputmanager.processstagingarea()     @ system.windows.input.inputmanager.processinput(inputeventargs input)     @ system.windows.input.inputprovidersite.reportinput(inputreport inputreport)     @ system.windows.interop.hwndmouseinputprovider.reportinput(intptr hwnd, inputmode mode, int32 timestamp, rawmouseactions actions, int32 x, int32 y, int32 wheel)     @ system.windows.interop.hwndmouseinputprovider.filtermessage(intptr hwnd, windowmessage msg, intptr wparam, intptr lparam, boolean& handled)     @ system.windows.interop.hwndsource.inputfiltermessage(intptr hwnd, int32 msg, intptr wparam, intptr lparam, boolean& handled)     @ ms.win32.hwndwrapper.wndproc(intptr hwnd, int32 msg, intptr wparam, intptr lparam, boolean& handled)     @ ms.win32.hwndsubclass.dispatchercallbackoperation(object o)     @ system.windows.threading.exceptionwrapper.internalrealcall(delegate callback, object args, int32 numargs)     @ system.windows.threading.exceptionwrapper.trycatchwhen(object source, delegate callback, object args, int32 numargs, delegate catchhandler)     @ system.windows.threading.dispatcher.legacyinvokeimpl(dispatcherpriority priority, timespan timeout, delegate method, object args, int32 numargs)     @ ms.win32.hwndsubclass.subclasswndproc(intptr hwnd, int32 msg, intptr wparam, intptr lparam)     @ ms.win32.unsafenativemethods.dispatchmessage(msg& msg)     @ system.windows.threading.dispatcher.pushframeimpl(dispatcherframe frame)     @ system.windows.threading.dispatcher.pushframe(dispatcherframe frame)     @ system.windows.application.rundispatcher(object ignore)     @ system.windows.application.runinternal(window window)     @ system.windows.application.run(window window)     @ myproject.src.app.main()