dotnet/wpf · error · ElementNotEnabledException

ElementNotEnabledException

Error message

ElementNotEnabledException

What it means

WindowsListViewGroup.CheckControlEnabled throws ElementNotEnabledException (no custom message) when SafeNativeMethods.IsWindowEnabled(_hwnd) reports the underlying ListView window is disabled. It is called at the start of ExpandOrCollapse, so Expand()/Collapse() on a disabled control is rejected as required by the UIA ExpandCollapse pattern contract.

Solutions

  1. Check the element's IsEnabled property (or IsWindowEnabled) before invoking Expand/Collapse and skip or wait.
  2. Wait for the blocking modal window to close and the control to re-enable, then retry.
  3. Catch ElementNotEnabledException and record the control as non-interactive instead of failing the run.

Example fix

// before
expandPattern.Expand();
// after
if (element.Current.IsEnabled) expandPattern.Expand();
else WaitForEnabled(element, timeout);
Defensive patterns

Strategy: validation

Validate before calling

if (!element.Current.IsEnabled) { WaitForEnabled(element, TimeSpan.FromSeconds(5)); }

Try / catch

try { expandPattern.Expand(); }
catch (ElementNotEnabledException) { log.Info("ListView disabled; skipping group expand"); }

Prevention

When it happens

Trigger: Calling ExpandCollapsePattern.Expand() or Collapse() on a ListView group whose hosting ListView window is disabled (IsWindowEnabled == false), e.g. while a modal dialog blocks the window.

Common situations: Automation run during a modal dialog, a disabled parent form, or the app intentionally disabling the list; test scripts that don't check IsEnabled before interacting.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/f09a49f094b226fe. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/UIAutomation/UIAutomationClientSideProviders/MS/Internal/AutomationProxies/WindowsListViewGroup.cs:406

        }

        int IGridProvider.ColumnCount
        {
            get
            {
                return GetColumnCount (_hwnd, ID);
            }
        }

        #endregion Grid Pattern

        #region ExpandCollapse Pattern

        private void CheckControlEnabled()
        {
            if (!SafeNativeMethods.IsWindowEnabled(_hwnd))
            {
                throw new ElementNotEnabledException();
            }
        }

        void IExpandCollapseProvider.Expand()
        {
            ExpandOrCollapse(false);
        }

        private bool IsCollapsed()
        {
            return IsCollapsed(_hwnd, _groupID);
        }

        internal static bool IsCollapsed(IntPtr hwnd, int groupID)
        {
            bool isCollapsed = false;
            NativeMethods.LVGROUP group = new NativeMethods.LVGROUP();
            group.Init(Marshal.SizeOf(typeof(NativeMethods.LVGROUP)));

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