cefsharp/CefSharp · error · ArgumentOutOfRangeException

Argument less than 10.

Error message

Argument less than 10. 

What it means

IntegratedMessageLoopBrowserProcessHandler drives CEF's message loop via a WPF DispatcherTimer. The interval (in milliseconds) must be at least 10; anything lower would flood the dispatcher with DoMessageLoopWork calls, starving the UI thread and destabilizing CEF's internal timing.

Source

Thrown at CefSharp.Wpf/HwndHost/Handler/IntegratedMessageLoopBrowserProcessHandler.cs:52

        private int interval;

        /// <summary>
        /// Default constructor
        /// </summary>
        /// <param name="dispatcher">WPF Dispatcher</param>
        /// <param name="dispatcherPriority">Priority at which <see cref="Cef.DoMessageLoopWork"/> is called using the Dispatcher</param>
        /// <param name="interval">the <see cref="Timer.Interval"/> in miliseconds (frame rate), for 30/60 times per second use
        /// <see cref="ThirtyTimesPerSecond"/>/<see cref="SixtyTimesPerSecond"/> respectively.</param>
        public IntegratedMessageLoopBrowserProcessHandler(Dispatcher dispatcher, DispatcherPriority dispatcherPriority = DispatcherPriority.Render, int interval = ThirtyTimesPerSecond)
        {
            if (dispatcher == null)
            {
                throw new ArgumentNullException(nameof(dispatcher));
            }

            if (interval < 10)
            {
                throw new ArgumentOutOfRangeException(nameof(interval), "Argument less than 10. ");
            }

            dispatcherTimer = new DispatcherTimer(dispatcherPriority, dispatcher)
            {
                Interval = TimeSpan.FromMilliseconds(interval)
            };

            dispatcherTimer.Tick += OnDispatcherTimerTick;
            dispatcherTimer.Start();

            this.dispatcher = dispatcher;
            this.dispatcher.ShutdownStarted += DispatcherShutdownStarted;
            this.dispatcherPriority = dispatcherPriority;
            this.interval = interval;

            Cef.ShutdownStarted += OnCefShutdownStarted;
        }

View on GitHub (pinned to 16bc6e0711)

Solutions

1. Use the provided constants ThirtyTimesPerSecond (≈33ms) or SixtyTimesPerSecond (≈16ms).
2. If a custom interval is needed, ensure it is >= 10.
3. Validate the interval before passing it.

Example fix

// before — too low
var handler = new IntegratedMessageLoopBrowserProcessHandler(dispatcher, DispatcherPriority.Render, 5);

// after — use a safe constant or validate
var handler = new IntegratedMessageLoopBrowserProcessHandler(
    dispatcher, DispatcherPriority.Render,
    IntegratedMessageLoopBrowserProcessHandler.SixtyTimesPerSecond);

const int minInterval = 10;
if (interval < minInterval)
{
    throw new ArgumentOutOfRangeException(nameof(interval),
        $"Interval must be >= {minInterval}ms, got {interval}");
}
var handler = new IntegratedMessageLoopBrowserProcessHandler(dispatcher, priority, interval);

When it happens

Trigger: Passing an interval value less than 10 to the constructor's interval parameter (default is ThirtyTimesPerSecond ≈ 33ms).

Common situations: Trying to achieve a higher frame rate than 100fps by passing a very small interval. Passing 0 or 1 by mistake (e.g. a computed value from an uninitialized variable).

Related errors

• Browser has already been created. BrowserSettings must be se
• Browser has already been created. RequestContext must be set
• viewPort.Scale must be greater than 0.
• {prop.Name} is required
• otherRequestContext

AI-assisted analysis of cefsharp/CefSharp@16bc6e0711 (2026-08-13). Data as JSON: /api/errors/29af44c39897fb20. Report an issue: GitHub.