cefsharp/CefSharp · info · Exception

This is an exception coming from C#

Error message

This is an exception coming from C#

What it means

This is a deliberately-thrown exception in the CefSharp.Example AsyncBoundObject.Error() method — demo code that shows how a C# method bound to JavaScript propagates exceptions back to JS. It is not a production error; it exists so the test suite and example pages can verify the error-handling pipeline between C# and JS.

Source

Thrown at CefSharp.Example/JavascriptBinding/AsyncBoundObject.cs:24

using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using CefSharp.Web;

namespace CefSharp.Example.JavascriptBinding
{
    public class AsyncBoundObject
    {
        //We expect an exception here, so tell VS to ignore
        [DebuggerHidden]
        public void Error()
        {
            throw new Exception("This is an exception coming from C#");
        }

        //We expect an exception here, so tell VS to ignore
        [DebuggerHidden]
        public int Div(int divident, int divisor)
        {
            return divident / divisor;
        }

        public string DivWithBlockingTaskCall(int dividend, int divisor)
        {
            var taskToWaitOn = ExecuteTaskBeforeDivision(dividend, divisor);
            taskToWaitOn.Wait();
            return taskToWaitOn.Result;
        }

        private async Task<string> ExecuteTaskBeforeDivision(int dividend, int divisor)
        {

View on GitHub (pinned to 16bc6e0711)

Solutions

1. This is expected behavior in the example — do not treat it as a real bug.
2. If you copied AsyncBoundObject into your app, remove or replace the Error() method.
3. Use try/catch in JavaScript (await obj.error()) to handle bound-object exceptions in your own binding code.

Example fix

// JavaScript caller
// before
await CefSharp.BindObjectAsync('asyncBoundObj');
await asyncBoundObj.error();

// after
try { await asyncBoundObj.error(); }
catch (e) { console.log('C# exception:', e); }

// In JavaScript
try { await asyncBoundObj.error(); }
catch (e) { console.log('Handled expected C# error:', e); }

When it happens

Trigger: Calling the bound object's Error() method from JavaScript (e.g. CefSharp.AsyncBoundObj.error()). Triggered only in the example browser app.

Common situations: Running the CefSharp.Example project and invoking the test button/handler that calls this bound method. Not encountered in production apps that don't reference AsyncBoundObject.

Related errors

• Expected Exception
• Nested Exception Invalid
• Nested Exception Canceled
• An IFrame instance is required.
• Unable to find parent TabPage

AI-assisted analysis of cefsharp/CefSharp@16bc6e0711 (2026-08-13). Data as JSON: /api/errors/a5d09b9c9da134c9. Report an issue: GitHub.