Unhandled exception

I'm getting an unhandled ArgumentOutOfRangeException when trying to select an item from the member list. Exception message is -

InvalidArgument=Value of '51' is not valid for 'index'.
Parameter name: index

StackTrace is -

at System.Windows.Forms.ImageList.Draw(Graphics g, Int32 x, Int32 y, Int32 width, Int32 height, Int32 index)
at System.Windows.Forms.ImageList.Draw(Graphics g, Int32 x, Int32 y, Int32 index)
at ActiproSoftware.SyntaxEditor.IntelliPromptMemberListItem.OnRender(DrawItemEventArgs e, IntelliPromptMemberListBox listBox)
at ActiproSoftware.SyntaxEditor.IntelliPromptMemberListBox.OnDrawItem(DrawItemEventArgs e)
at System.Windows.Forms.ListBox.WmReflectDrawItem(Message& m)
at System.Windows.Forms.ListBox.WndProc(Message& m)
at ActiproSoftware.SyntaxEditor.IntelliPromptMemberListBox.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.SendMessage(HandleRef hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at System.Windows.Forms.Control.SendMessage(Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.Control.ReflectMessageInternal(IntPtr hWnd, Message& m)
at System.Windows.Forms.Control.WmOwnerDraw(Message& m)
at System.Windows.Forms.Control.WmDrawItem(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at System.Windows.Forms.Application.ParkingWindow.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.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
at System.Windows.Forms.Control.DefWndProc(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ListBox.WndProc(Message& m)
at ActiproSoftware.SyntaxEditor.IntelliPromptMemberListBox.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.SendMessage(HandleRef hWnd, Int32 msg, Int32 wParam, Int32 lParam)
at System.Windows.Forms.Control.SendMessage(Int32 msg, Int32 wparam, Int32 lparam)
at System.Windows.Forms.ListBox.NativeSetSelected(Int32 index, Boolean value)
at System.Windows.Forms.ListBox.set_SelectedIndex(Int32 value)
at ActiproSoftware.SyntaxEditor.IntelliPromptMemberListBox.set_SelectedIndex(Int32 value)
at ActiproSoftware.SyntaxEditor.IntelliPromptMemberList.ActiproSoftware.SyntaxEditor.ISyntaxEditorEditModeHandler.OnKeyTyping(KeyTypingEventArgs e)
at ActiproSoftware.SyntaxEditor.SyntaxEditor.a(EditorView A_0, Keys A_1, Char A_2, Boolean A_3)
at ActiproSoftware.SyntaxEditor.SyntaxEditor.OnKeyDown(KeyEventArgs e)
at System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
at System.Windows.Forms.Control.ProcessKeyMessage(Message& m)
at System.Windows.Forms.Control.WmKeyChar(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at ActiproSoftware.SyntaxEditor.SyntaxEditor.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(ApplicationContext context)
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
at GenApp.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()