"Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))"

Question

I am trying to use an application, the application is working fine, i am trying to edit the existing item in the application. while clicking the edit am getting the following error,

System.Runtime.InteropServices.COMException was unhandled   Message="Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))"   Source="System.Windows.Forms"   ErrorCode=-2147221164   StackTrace:        at System.Windows.Forms.UnsafeNativeMethods.CoCreateInstance(Guid& clsid, Object punkOuter, Int32 context, Guid& iid)        at System.Windows.Forms.AxHost.CreateWithoutLicense(Guid clsid)        at System.Windows.Forms.AxHost.CreateWithLicense(String license, Guid clsid)        at System.Windows.Forms.AxHost.CreateInstanceCore(Guid clsid)        at System.Windows.Forms.AxHost.CreateInstance()        at System.Windows.Forms.AxHost.GetOcxCreate()        at System.Windows.Forms.AxHost.TransitionUpTo(Int32 state)        at System.Windows.Forms.AxHost.CreateHandle()        at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)        at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)        at System.Windows.Forms.AxHost.EndInit()        at bulk_lister.frm_edititem.InitializeComponent() in New Bulklister\new bulklister\bulk_lister\bulk_lister\frm_edititem.designer.cs:line 4248        at bulk_lister.frm_edititem..ctor(Int32 userid, Int32 intListingId) in New Bulklister\new bulklister\bulk_lister\bulk_lister\frm_edititem.cs:line 187        at bulk_lister.parent_form.funEditItem_fromrghtclktoolStrip_edititm() in New Bulklister\new bulklister\bulk_lister\bulk_lister\parent_form.cs:line 1313        at bulk_lister.parent_form.rghtclktoolStrip_edititm_Click(Object sender, EventArgs e) in New Bulklister\new bulklister\bulk_lister\bulk_lister\parent_form.cs:line 1233        at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)        at System.Windows.Forms.ToolStripButton.OnClick(EventArgs e)        at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)        at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)        at System.Windows.Forms.ToolStripItem.FireEventInteractive(EventArgs e, ToolStripItemEventType met)        at System.Windows.Forms.ToolStripItem.FireEvent(EventArgs e, ToolStripItemEventType met)        at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)        at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)        at System.Windows.Forms.Control.WndProc(Message& m)        at System.Windows.Forms.ScrollableControl.WndProc(Message& m)        at System.Windows.Forms.ToolStrip.WndProc(Message& m)        at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)        at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)        at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)        at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)        at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)        at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)        at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)        at System.Windows.Forms.Application.Run(Form mainForm)        at bulk_lister.Program.Main() inNew Bulklister\new bulklister\bulk_lister\bulk_lister\Program.cs:line 17        at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)        at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args)        at System.Runtime.Hosting.ManifestRunner.Run(Boolean checkAptModel)        at System.Runtime.Hosting.ManifestRunner.ExecuteAsAssembly()        at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)        at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext)        at System.Activator.CreateInstance(ActivationContext activationContext)        at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()        at System.Threading.ThreadHelper.ThreadStart_Context(Object state)        at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)        at System.Threading.ThreadHelper.ThreadStart()   InnerException:  

Its with the Dll file that i have used with my application. i have tried to registered this dll file using regsvr32 but i cant make it.

DLL:AxInterop.DHTMLEDLib.dll & Interop.DHTMLEDLib.dll 

Any one have idea on this exception?

Answer 1

What is the target platform of your application? I think you should set the platform to x86, do not set it to Any CPU.

Answer 2

This is probably not a solution to your problem, but a suggestion just in case (I know I ran into a similar problem before but not with a .NET application).

If you are on a 64-bit machine, there are 2 regsvr32.exe files; One is in \Windows\System32 and the other one is in \Windows\SysWOW64.

You cannot register 64-bit COM-objects with the 32-bit version, but you can do it vice versa. I'd try registering your DLL with both regsvr32.exe files explicitly (i.e. typing "C:\Windows\System32\regsvr32.exe /i mydll.dll" and then "C:\Windows\SysWOW64\regsvr32.exe /i mydll.dll") and seeing if that helps...