Webclient Issue - Error Message: Value cannot be null

We installed NAV2015 on our database – and facing issue with the web client.

Web client opens ok and runs some pages but then stops with error "A server error has occurred, and the content cannot be displayed. Refresh the page or open a new browser window"

Error message: Value cannot be null.

Event Viewer says:

Error accessing Website Microsoft Dynamics NAV 2015 Web Client
URL: http://XXXXXX:8080/XXXX/WebClient/Services/CallbackService.svc/InvokeHandler
Type: System.ArgumentNullException
Message: Value cannot be null.
Parameter name: form
StackTrace:
   at Microsoft.Dynamics.Framework.UI.EventBlock..ctor(LogicalForm form)
   at Microsoft.Dynamics.Nav.Client.UIPatterns.ExpressionPattern.Evaluate(LogicalControl fieldTarget)
   at Microsoft.Dynamics.Nav.Client.UIPatterns.VisibleFormHostControlExpressionPattern.Evaluate(LogicalControl fieldTarget)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at Microsoft.Dynamics.Nav.Client.DataBinder.NstDataAccess.OpenForm(LogicalForm mainForm, Collection`1 subForms)
   at Microsoft.Dynamics.Nav.Client.UIPatterns.OnFormOpeningPattern.OpenForm(LogicalForm form)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at Microsoft.Dynamics.Framework.UI.UX2006.EmbeddedListView.OnFormBuilt(EventArgs e)
   at Microsoft.Dynamics.Nav.Client.Builder.NavSessionHelper.BuildForm(LogicalForm form)
   at Microsoft.Dynamics.Nav.Client.FormBuilder.PageBuilder.Build(MasterPage definition, BindingManager bindingManager, UIBuilderContext context)
   at Microsoft.Dynamics.Nav.Client.FormBuilder.UIBuildManager.BuildPage(MasterPage pageDef, UIBuilderContext context)
   at Microsoft.Dynamics.Nav.Client.FormBuilder.BuilderSession.CreateLogicalForm(MasterPage metadata, FormState formState)
   at Microsoft.Dynamics.Nav.Client.FormBuilder.BuilderSession.CreateLogicalForm(Int32 formId, FormState formState, Int32 retryCounter)
   at Microsoft.Dynamics.Nav.Client.FormBuilder.BuilderSession.CreateLogicalForm(String name)
   at Microsoft.Dynamics.Framework.UI.UISession.CreateLogicalForm(String name, Boolean reuseActiveForm)
   at Microsoft.Dynamics.Framework.UI.UX2006.NavigationService.OpenEmbeddedForm(String formName)
   at Microsoft.Dynamics.Framework.UI.UX2006.NavigateToFormAction.InvokeCore(LogicalControl logicalControl, Object state, UISession uiSession)
   at Microsoft.Dynamics.Nav.Client.Actions.NavNavigateToFormAction.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.UX2006.NavigationService.NavigateToNode(LogicalControl logicalControl, NavigationNode node)
   at Microsoft.Dynamics.Framework.UI.UX2006.NavigateInteraction.InvokeCore(NavigateInteractionInput logicalInteractionInput)
   at Microsoft.Dynamics.Framework.UI.InteractionInvoker.Invoke[T](String interactionName, Action`1 invokeMethod, T input)
   at Microsoft.Dynamics.Framework.UI.LogicalInteraction`1.Invoke(T logicalInteractionInput)
   at Microsoft.Dynamics.Framework.UI.InteractionManager.<>c__DisplayClass8.<InvokeInteractions>b__4()
Source: Microsoft.Dynamics.Framework.UI

Finally, the new feature called “Social Listening” is causing the issue.This new feature is introduced after NAV2015 RTM and uses a Dll and some pages use the fact boxes related to “Social Listening” and Dll which is required is missing in Database.

Solution:
1. Open Control Add-In’s page from RTC or Webclient
2. Add below line using New action (You can check Codeunit 2 Company-Initialize function InsertClientAddIns to copy instead of typing)

c Click Import and choose the path where Social Listening Dll is located.