{"record":{"id":"fafcc76f3caef16c","repo":"cefsharp/CefSharp","slug":"browser-has-already-been-created-browsersettings-fafcc7","errorCode":null,"errorMessage":"Browser has already been created. BrowserSettings must be set before the underlying CEF browser is created.","messagePattern":"Browser has already been created\\. BrowserSettings must be set before the underlying CEF browser is created\\.","errorType":"exception","errorClass":"Exception","httpStatus":null,"severity":"error","filePath":"CefSharp.Wpf/HwndHost/ChromiumWebBrowser.cs","lineNumber":225,"sourceCode":"        {\n            get\n            {\n                return Interlocked.CompareExchange(ref disposeSignaled, 1, 1) == 1;\n            }\n        }\n\n        /// <summary>\n        /// Gets or sets the browser settings.\n        /// </summary>\n        /// <value>The browser settings.</value>\n        public IBrowserSettings BrowserSettings\n        {\n            get { return browserSettings; }\n            set\n            {\n                if (browserCreated)\n                {\n                    throw new Exception(\"Browser has already been created. BrowserSettings must be \" +\n                                        \"set before the underlying CEF browser is created.\");\n                }\n\n                //New instance is created in the constructor, if you use\n                //xaml to initialize browser settings then it will also create a new\n                //instance, so we dispose of the old one\n                if (browserSettings != null && browserSettings.AutoDispose)\n                {\n                    browserSettings.Dispose();\n                }\n\n                browserSettings = value;\n            }\n        }\n        /// <summary>\n        /// Gets or sets the request context.\n        /// </summary>\n        /// <value>The request context.</value>","sourceCodeStart":207,"sourceCodeEnd":243,"githubUrl":"https://github.com/cefsharp/CefSharp/blob/16bc6e0711a4945be17e8bc4bc7ccf9469f3fdec/CefSharp.Wpf/HwndHost/ChromiumWebBrowser.cs#L207-L243","documentation":"BrowserSettings configures the underlying CEF browser (cache path, webgl, fonts, etc.) and must be applied before the native browser instance is created. Once the browserCreated flag is true, the native browser is live and its settings are immutable; assigning a new BrowserSettings instance at that point throws.","triggerScenarios":"Setting the BrowserSettings property after the control has been loaded into the visual tree, after CreateBrowser was called, or after IsBrowserInitialized has become true.","commonSituations":"Assigning BrowserSettings in a Loaded event handler, a data-binding callback, or any code path that runs after the WPF control has rendered and triggered browser creation.","solutions":["Set BrowserSettings in XAML or in the constructor before the control is added to the visual tree.","If configuring in code, set it immediately after `new ChromiumWebBrowser()` and before adding the control to a parent.","Use CefSettings (global) for settings that must change after browser creation."],"exampleFix":"// before — throws because browser is already created\nprivate void OnLoaded(object s, EventArgs e)\n{\n    browser.BrowserSettings = new BrowserSettings { WebGl = CefState.Disabled };\n}\n\n// after — set before visual tree attachment\nvar browser = new ChromiumWebBrowser\n{\n    BrowserSettings = new BrowserSettings { WebGl = CefState.Disabled }\n};\n// then add browser to the layout","handlingStrategy":"validation","validationCode":"if (browser.browserCreated) // if accessible; otherwise check IsBrowserInitialized\n{\n    // cannot set BrowserSettings now\n    return;\n}\nbrowser.BrowserSettings = settings;","typeGuard":null,"tryCatchPattern":"try\n{\n    browser.BrowserSettings = settings;\n}\ncatch (Exception ex) when (ex.Message.Contains(\"Browser has already been created\"))\n{\n    Log.Warn(\"BrowserSettings cannot be changed after browser creation\", ex);\n}","preventionTips":["Set BrowserSettings in XAML or immediately after `new ChromiumWebBrowser()`.","Treat BrowserSettings as write-once: configure before adding the control to the visual tree.","Use CefSettings for global settings that can survive across browser instances."],"tags":["browser-settings","lifecycle","validation","wpf-hwndhost"],"backgroundTag":null,"analyzedSha":"16bc6e0711a4945be17e8bc4bc7ccf9469f3fdec","analyzedAt":"2026-08-13T19:57:05.828Z","schemaVersion":2},"datasetVersion":"2026-08-14T00:17:13.853Z"}