cefsharp/CefSharp · error · Exception

A call to WithCachePath has already been made, it's not poss

Error message

A call to WithCachePath has already been made, it's not possible to share settings with another RequestContext.

What it means

The mirror of error 16: RequestContextBuilder.ThrowExceptionIfCustomSettingSpecified throws when you call WithSharedSettings after WithCachePath (or any method that populated _settings) has already been used. You cannot share another context's storage once custom settings are in play. Thrown as a plain System.Exception with parameter-free message.

Source

Thrown at CefSharp.Core/RequestContextBuilder.cs:33

    public class RequestContextBuilder
    {
        private RequestContextSettings _settings;
        private IRequestContext _otherContext;
        private RequestContextHandler _handler;

        void ThrowExceptionIfContextAlreadySet()
        {
            if (_otherContext != null)
            {
                throw new Exception("A call to WithSharedSettings has already been made, it is no possible to provide custom settings.");
            }
        }

        void ThrowExceptionIfCustomSettingSpecified()
        {
            if (_settings != null)
            {
                throw new Exception("A call to WithCachePath has already been made, it's not possible to share settings with another RequestContext.");
            }
        }
        /// <summary>
        /// Create the actual RequestContext instance
        /// </summary>
        /// <returns>Returns a new RequestContext instance.</returns>
        public IRequestContext Create()
        {
            if (_otherContext != null)
            {
                return new CefSharp.Core.RequestContext(_otherContext, _handler);
            }

            if (_settings != null)
            {
                return new CefSharp.Core.RequestContext(_settings.settings, _handler);
            }

View on GitHub (pinned to 16bc6e0711)

Solutions

Use a fresh builder for each distinct strategy (share vs customise).
If you previously set WithCachePath, do not call WithSharedSettings on the same builder - share instead at browser creation.
Reset builder state or use a factory that returns the correct pre-configured builder per strategy.
Add an integration test covering both code paths to catch the contradictory ordering early.

Example fix

// before - throws
var ctx = RequestContext.Configure()
    .WithCachePath(@"C:\cache")
    .WithSharedSettings(parent) // throws
    .Create();

// after - one strategy per builder
var custom = RequestContext.Configure().WithCachePath(@"C:\cache").Create();

Defensive patterns

Strategy: validation

Validate before calling

// Decide share-vs-customise before configuring the builder.
RequestContextBuilder b = share ? RequestContext.Configure().WithSharedSettings(parent)
                                : RequestContext.Configure().WithCachePath(cache);

Type guard

public static bool CanShare(RequestContextBuilder b) => b.GetSettings() == null; // (requires exposing state)

Try / catch

try { return builder.WithSharedSettings(parent).Create(); }
catch (Exception ex) when (ex.Message.Contains("WithCachePath has already been made"))
{ return RequestContext.Configure().WithSharedSettings(parent).Create(); }

Prevention

Use one builder per strategy; do not reuse across share/custom calls
Reset or recreate the builder when switching strategy
Test both ordering branches

When it happens

Trigger: Chaining .WithCachePath(...).WithSharedSettings(parent); calling WithSharedSettings twice after a custom setting was added; merging a shared and a custom configuration in one builder.

Common situations: Builder reused across requests accumulating both kinds of calls; template builder that includes cache path, then a caller tries to share; refactor joining two configurations.

Related errors

AI-assisted analysis of cefsharp/CefSharp@16bc6e0711 (2026-08-13). Data as JSON: /api/errors/b1e40896de122ade. Report an issue: GitHub.