I'm facing null reference issue with multiple CM Sitecore Setup. Below is the environment details.
Servers 2
Sitecore 8.0 update 6
Very minimal access to infrastructure.
DisableClientBrowsing is set to true.
Scalability Setting config is disabled.
ERROR Application error. Exception: System.Web.HttpUnhandledException Message: Exception of type 'System.Web.HttpUnhandledException' was thrown. Source: System.Web
at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.sitecore_shell_applications_content_manager_default_aspx.ProcessRequest(HttpContext context) in c:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\root\68275d57\e975e24f\App_Web_py4csts0.3.cs:line 0
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)Nested Exception
Exception: System.Reflection.TargetInvocationException Message: Exception has been thrown by the target of an invocation. Source: mscorlib at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at Sitecore.Reflection.ReflectionUtil.InvokeMethod(MethodInfo method, Object[] parameters, Object obj) at Sitecore.Web.UI.Sheer.ClientPage.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)Nested Exception
Exception: System.NullReferenceException Message: Object reference not set to an instance of an object. Source: Sitecore.Client at Sitecore.Shell.Applications.ContentManager.ContentEditorForm.OnLoad(EventArgs e)