dotnet/wpf · error · ElementNotEnabledException

ElementNotEnabledException

Error message

ElementNotEnabledException

What it means

WindowsToolbar's private Invoke() throws ElementNotEnabledException when either the toolbar window is disabled (IsWindowEnabled false) or the specific button reports disabled via TB_ISBUTTONENABLED. UIA requires this exception when the target element cannot accept invocation because it is disabled.

Solutions

1. Check the button's UIA IsEnabled property before invoking and wait for it to become enabled
2. Enable the application state that enables the command (e.g. make a selection first)
3. Catch ElementNotEnabledException and retry with a bounded wait

Example fix

// before
copyButton.Invoke();
// after
if (copyButton.Current.IsEnabled) copyButton.Invoke(); else WaitFor(() => copyButton.Current.IsEnabled).Invoke();

if (!toolbarButton.Current.IsEnabled) throw new SkipInvokeException();

bool IsEnabled(AutomationElement el) => el.Current.IsEnabled;

try { toolbarButton.Invoke(); } catch (ElementNotEnabledException) { WaitFor(() => toolbarButton.Current.IsEnabled, timeout); toolbarButton.Invoke(); }

When it happens

Trigger: Calling InvokePattern.Invoke() on a toolbar button whose command is disabled (grayed out) or whose toolbar window is disabled.

Common situations: Clicking cut/copy buttons with nothing selected; invoking buttons grayed by app state; automation firing during modal/disabled periods.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• ElementNotEnabledException
• Element is not enabled.
• ElementNotAvailableException
• ElementNotEnabledException
• SR.DataGrid_AutomationInvokeFailed

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/6a1e00b05c5b8dbc. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/UIAutomation/UIAutomationClientSideProviders/MS/Internal/AutomationProxies/WindowsToolbar.cs:645

                {
                    itemId = "Item " + tbb.idCommand.ToString(CultureInfo.CurrentCulture);
                }
            }
        }

        private string GetItemToolTipText()
        {
            IntPtr hwndToolTip = Misc.ProxySendMessage(_hwnd, NativeMethods.TB_GETTOOLTIPS, IntPtr.Zero, IntPtr.Zero);
            return Misc.GetItemToolTipText(_hwnd, hwndToolTip, _idCommand);
        }

        private void Invoke()
        {
            // Make sure that the toolbar is enabled, and that the toolbar button is enabled.
            if (!SafeNativeMethods.IsWindowEnabled(_hwnd)
                || Misc.ProxySendMessageInt(_hwnd, NativeMethods.TB_ISBUTTONENABLED, new IntPtr(_idCommand), IntPtr.Zero) == 0)
            {
                throw new ElementNotEnabledException();
            }

            // Check that button can be clicked (button not hidden)
            // This state could change anytime so success is not guaranteed
            if (Misc.ProxySendMessageInt(_hwnd, NativeMethods.TB_ISBUTTONHIDDEN, new IntPtr(_idCommand), IntPtr.Zero) != 0)
            {
                throw new InvalidOperationException(SR.OperationCannotBePerformed);
            }

            // Click the center of the button
            // TB_CHECKBUTTON and TB_PRESSBUTTON messages are not used as they will not trigger proper notifications
            // Need to check that this button is visible to the mouse
            Rect boundingRectangle = BoundingRectangle;

            if (boundingRectangle.IsEmpty)
            {
                throw new InvalidOperationException(SR.OperationCannotBePerformed);
            }

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