An internal error has occured. Multiple concurrent calls have been issued to the server from this cl

Hello,

we have a problem with one of our control Add-ins / page.

For Visualization we developed an add-in that is placed on a page in Dynamics Nav.
When the user opens the Card, he gets an error, but not really every time,
we don't know when this error really occurs.

Error: An internal error has occured. Multiple concurrent calls have been issued to the server from this Client.

This Error occurs when to user opens the Card the first time in his session, at the most. Sometimes after a several times closing and opening the page, also.

StackTrace:

at Microsoft.Dynamics.Nav.Client.DataBinder.NstDataAccess.GetPage(PageRequestDefinition pageRequestDefinition, Bookmark bookmark)
at Microsoft.Dynamics.Nav.Client.DataBinder.NavInitialPageReader.ReadData(DataReaderFillOptions options)
at Microsoft.Dynamics.Nav.Client.DataBinder.NavInitialPageReader.InitialFill(DataReaderFillOptions options)
at Microsoft.Dynamics.Nav.Client.DataBinder.NavDataReader.FillFirstRowEntryCollection(DataReaderFillOptions options)
at Microsoft.Dynamics.Framework.UI.VirtualRows.FillFirstBlock(DataReaderFillOptions fillOptions)
at Microsoft.Dynamics.Framework.UI.BindingManager.DoFill(DataReaderFillOptions fillOptions)
at Microsoft.Dynamics.Framework.UI.BindingManager.Fill(BindingManagerFillOptions options)
at Microsoft.Dynamics.Framework.UI.BindingManager.Fill()
at Microsoft.Dynamics.Framework.UI.LogicalForm.LoadDataInternal()
at Microsoft.Dynamics.Framework.UI.LogicalForm.LoadData()
at Microsoft.Dynamics.Framework.UI.Windows.LogicalFormAdapterBase.OnLoadData()
at Microsoft.Dynamics.Framework.UI.Windows.LogicalFormAdapterBase.LoadDataInternal()
at Microsoft.Dynamics.Framework.UI.Windows.LogicalFormAdapterBase.Load(LogicalControl originatingLogicalControl, Boolean loadDataDelayed)
at Microsoft.Dynamics.Framework.UI.Windows.ClientSessionBase.OnFormToShow(LogicalForm logicalFormToShow, LogicalControl originatingLogicalControl)
at Microsoft.Dynamics.Framework.UI.WinForms.ClientSession.OnFormToShow(LogicalForm logicalFormToShow, LogicalControl originatingLogicalControl)
at Microsoft.Dynamics.Framework.UI.Windows.ClientSessionBase.OnFormToShow(FormSessionEventArgs e)
at Microsoft.Dynamics.Framework.UI.Windows.ClientSessionBase.FormToShow(Object sender, FormSessionEventArgs e)
at Microsoft.Dynamics.Framework.UI.UISession.OnFormToShow(FormSessionEventArgs e)
at Microsoft.Dynamics.Framework.UI.UISession.ShowForm(LogicalForm logicalForm, LogicalForm parentForm)
at Microsoft.Dynamics.Nav.Client.Actions.NavOpenTaskPageAction.ShowForm(LogicalForm childForm, LogicalForm parentForm, UISession uiSession, FormState formState)
at Microsoft.Dynamics.Nav.Client.Actions.NavOpenTaskPageAction.InvokeCore(LogicalControl logicalControl, Object state, UISession uiSession)
at Microsoft.Dynamics.Framework.UI.LogicalAction.InvokeCoreWithErrorHandling(LogicalControl logicalControl, Object state, UISession uiSession)
at Microsoft.Dynamics.Framework.UI.LogicalAction.DoInvoke(LogicalControl logicalControl, UISession uiSession)
at Microsoft.Dynamics.Framework.UI.ActionControl.Invoke()
at Microsoft.Dynamics.Framework.UI.Windows.ActionsHelper.<>c__DisplayClassa.<ModalitySafeInvoke>b__8()
at Microsoft.Dynamics.Framework.UI.Windows.ActionsHelper.ModalitySafe(Action action)
at Microsoft.Dynamics.Framework.UI.Windows.ActionsHelper.ModalitySafeInvoke(ActionControl actionControl)
at Microsoft.Dynamics.Framework.UI.Windows.ActionControlAdapterBase.DefaultInvokeAction(LogicalControlAdapter adapter, ActionControl actionControl)
at Microsoft.Dynamics.Framework.UI.Windows.ActionControlAdapterBase.DefaultInvokeAction(LogicalControlAdapter adapter)
at Microsoft.Dynamics.Framework.UI.Windows.ActionControlAdapterBase.OnInvoke()
at Microsoft.Dynamics.Framework.UI.WinForms.ActionLinkControlAdapter.<InitializeNativeControl>b__0(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at Microsoft.Dynamics.Framework.UI.WinForms.Controls.ImageLinkLabel.OnClick(EventArgs e)
at Microsoft.Dynamics.Framework.UI.WinForms.Controls.ImageLinkLabel.ProcessDialogKey(Keys keyData)
at System.Windows.Forms.Control.PreProcessMessage(Message& msg)
at System.Windows.Forms.Control.PreProcessControlMessageInternal(Control target, Message& msg)
at System.Windows.Forms.Application.ThreadContext.PreTranslateMessage(MSG& msg)

When the Add - In - Handle is Created, a function is called, async.

GenericEventDelegate onAddInReady = (paramSender, paramEventArg) => AddInReady(paramSender, paramEventArg);
onAddInReady.BeginInvoke(sender, e, OnThreadExit, null);

This will NAV tell to get all the data needed and after query done, the data will be send to control add-in. The whole process takes about 2 secondes.

You may have an idead?