ErrLookup › cefsharp/CefSharp

cefsharp/CefSharp

.NET (WPF and Windows Forms) bindings for the Chromium Embedded Framework · C# · 778 source files

Analyzed at 16bc6e0711 on 2026-08-13. 107 documented errors.

Code / MessageTypeSeverityTags
Current OS version is less than Windows 10. Applications not
exception critical csharp, cefsharp, windows, manifest, os-version, deployment
IBrowser
exception error csharp, cefsharp, devtools, object-disposed, lifecycle, async
Unable to add MessageId {0} to queuedCommandResults Concurre
exception error csharp, cefsharp, devtools, internal-invariant, concurrency
Unable to invoke ExecuteDevToolsMethod on CEF UI Thread.
exception error csharp, cefsharp, devtools, threading, ui-thread, lifecycle
Failed to execute dev tools method {0}.
exception error csharp, cefsharp, devtools, native-call, initialization
Generated MessageId {0} doesn't match returned Message Id {1
exception error csharp, cefsharp, devtools, internal-invariant, version-mismatch
Not currently supported.
exception error csharp, cefsharp, devtools, serialization, not-implemented, base64
{prop.Name} is required
validation error csharp, cefsharp, devtools, serialization, validation, required-field
otherRequestContext
validation error csharp, cefsharp, request-context, argument-null, validation
requestContextHandler
validation error csharp, cefsharp, request-context, argument-null, validation, handler
settings
validation error csharp, cefsharp, request-context, argument-null, validation, settings
A call to WithSharedSettings has already been made, it is no
exception error csharp, cefsharp, request-context, builder, fluent, misconfiguration
A call to WithCachePath has already been made, it's not poss
exception error csharp, cefsharp, request-context, builder, fluent, misconfiguration
other
validation error csharp, cefsharp, request-context, builder, argument-null, validation
request
validation error csharp, cefsharp, url-request, argument-null, validation
urlRequestClient
validation error argument-null, url-request, cefscore-core, constructor
Frame is invalid, unable to continue.
exception error frame-invalid, download, lifecycle, cefscore-core
frame
validation error argument-null, frame, download, async
Timeout greater than Maximum allowable value of {UInt32.MaxV
validation error argument-out-of-range, timeout, evaluate-script
Unable to Initialize Cef
exception critical cef-initialization, dependency, native-binaries, startup
This is an exception coming from C#
exception info example-code, js-binding, intentional, exception-demo
Expected Exception
exception info example-code, js-binding, async, intentional, exception-demo
Nested Exception Invalid
exception info example-code, js-binding, nested-exception, intentional
Nested Exception Canceled
exception info example-code, js-binding, nested-exception, intentional
An IFrame instance is required.
validation error argument-null, frame, scripted-methods, example-code
An instance of the underlying offscreen browser has already
exception error offscreen, browser-created, lifecycle, double-init
RenderHandler cannot be null. Use DefaultRenderHandler unles
exception error offscreen, render-handler, screenshot, null-reference
ScreenshotOrNull and ScreenshotAsync can only be used in com
exception error offscreen, render-handler, screenshot, type-mismatch
{nameof(viewport)}.{nameof(viewport.Scale)} must be greater
validation error offscreen, screenshot, viewport, argument
Unable to find parent TabPage
exception error winforms, tab-control, control-hierarchy, example-code
Unexpected failure of calling CEF->GetZoomLevelAsync
exception warning winforms, zoom, task-continuation, example-code, unobserved-exception
Browser has already been created. BrowserSettings must be se
exception error cefwsharp, winforms, lifecycle, browser-settings
BrowserSettings can only be of type {0} or null
exception error cefwsharp, winforms, type-mismatch, browser-settings
Browser has already been created. RequestContext must be set
exception error cefwsharp, winforms, lifecycle, request-context
RequestContext can only be of type {0} or null
exception error cefwsharp, winforms, type-mismatch, request-context
IBrowser instance is no longer valid. Control.Handle was lik
exception error cefwsharp, winforms, lifecycle, navigation
{nameof(viewPort)}.{nameof(viewPort.Scale)} must be greater
validation error cefwsharp, screenshot, validation, devtools
IBrowserHost is null, you've likely call this method before
exception error cefwsharp, winforms, experimental, hwnd, lifecycle
IBrowser instance is null. Browser has likely not finished i
exception error cefwsharp, winforms, lifecycle, mainframe
This method can only be called on the CEF UI thread.Use Cef.
exception error cefwsharp, winforms, threading, interop
Screenshot already in progress, you must wait for the previo
exception error cefwsharp, wpf, screenshot, concurrency
Browser has not yet finished initializing or is being dispos
exception error cefwsharp, wpf, screenshot, lifecycle
Unable to take screenshot while browser is loading
exception error cefwsharp, wpf, screenshot, navigation
IBrowserHost is null
exception error cefwsharp, wpf, screenshot, lifecycle
Replace not implemented yet
exception error cefwsharp, wpf, example, tabcontrol, notimplemented
Native access to touch keyboard APIs not supported on this O
exception error cefwsharp, wpf, platform, touchkeyboard, windows
Please provide a valid command parameter for binding
exception error cefwsharp, wpf, example, commands, validation
Browser has already been created. BrowserSettings must be se
exception error cefwsharp, wpf, lifecycle, browser-settings
Browser has already been created. RequestContext must be set
exception error cefwsharp, wpf, lifecycle, request-context
RequestContext can only be of type {0} or null
validation error cefwsharp, wpf, type-mismatch, request-context
Unexpected failure of calling CEF->GetZoomLevelAsync
exception warning cef, wpf, zoom-level, task-continuation, lifecycle
Invalid size, must be greater than 0,0
validation error wpf, browser-creation, size, validation
Browser has already been created. BrowserSettings must be se
exception error browser-settings, lifecycle, validation, wpf-hwndhost
Browser has already been created. RequestContext must be set
exception error request-context, lifecycle, validation, wpf-hwndhost
RequestContext can only be of type {0} or null
validation error request-context, type-validation, wpf-hwndhost
Unexpected failure of calling CEF->GetZoomLevelAsync
exception warning cef, wpf-hwndhost, zoom-level, task-continuation, lifecycle
Cef.Initialize() failed.Check the log file see https://githu
exception critical cef-initialization, native-deps, startup, wpf-hwndhost
Cef.IsInitialized was false!.Check the log file for errors!.
exception critical cef-initialization, lifecycle, shutdown, startup, wpf-hwndhost
viewPort.Scale must be greater than 0.
validation error screenshot, viewport, validation, wpf-hwndhost
The ChromiumWebBrowser instance creates the underlying Chrom
exception error browser-initialization, lifecycle, async, wpf-hwndhost
Browser has been disposed
exception error disposal, lifecycle, object-disposed, wpf-hwndhost
Argument less than 10.
validation error message-loop, timer, validation, wpf-hwndhost
Can only be used when CEF is integrated into your WPF Messag
exception error rendering, message-loop, configuration, wpf
CookieManager
exception error cookies, disposal, async, object-disposed
NotFound
exception critical native-deps, libcef, startup, file-not-found
UseAnyCpuAssemblyResolver has already been called, call
exception error any-cpu, assembly-resolver, startup, configuration
Unable to load for arch {env}
exception critical any-cpu, native-deps, architecture, startup, file-not-found
Unable to locate required Cef/CefSharp dependencies:
exception critical native-deps, dependency-check, startup, deployment
RequestContext has already been initialized,
exception error request-context, preferences, lifecycle, handler
Please provide a valid mimeType
validation error resource-handler, validation, mime-type, constructor, cefsharp
Please provide a valid array
validation error resource-handler, validation, null-reference, constructor, cefsharp
Unable to load byte[] with length 0.
validation error resource-handler, validation, empty-data, constructor, cefsharp
Cef.Shutdown has already been called, it's no longer possibl
exception critical lifecycle, shutdown, threading, ui-thread, cefsharp
converter
exception error validation, null-reference, datetime, configuration, cefsharp
manager
exception error cookie-manager, validation, null-reference, constructor, cefsharp
CookieManager store is not initialized.
exception error cookie-manager, lifecycle, initialization, race-condition, cefsharp
Please provide a valid mimeType
exception error resource-handler, validation, mime-type, constructor, cefsharp
Please provide a valid filePath
exception error resource-handler, validation, null-reference, constructor, cefsharp
Unable to create FileResourceHandler
exception error resource-handler, file-not-found, io, path, cefsharp
{GetType().Name}.{memberName} can no longer be modified, set
exception error lifecycle, configuration, immutable, settings, cefsharp
name
exception error javascript-binding, validation, null-reference, registration, cefsharp
value
exception error javascript-binding, validation, null-reference, registration, cefsharp
To enable synchronous JS bindings set WcfEnabled true in Cef
exception error cefsharp, javascript-binding, wcf, configuration, initialization-order, net-framework
Object already bound with name:{name}
exception error cefsharp, javascript-binding, duplicate-registration, naming
Registering of .Net framework built in types is not supporte
exception error cefsharp, javascript-binding, type-restriction, winforms, wpf
Method {0} not found on Object of Type {1}
exception error cefsharp, javascript-binding, method-not-found, interop-naming, sync
Could not execute method: {name}({parameters}) {optional: -
exception error cefsharp, javascript-binding, method-invocation, wrapped-exception, sync
Property {0} not found on Object of Type {1}
exception error cefsharp, javascript-binding, property-not-found, interop-naming
Unable to convert Enum
exception error cefsharp, json, enum, serialization, system-text-json
Cef.Initialize() failed.Check the log file see https://githu
exception critical cefsharp, cef-initialization, configuration, native-dependencies, startup
Cef.IsInitialized was false!.Check the log file for errors!.
exception critical cefsharp, cef-initialization, lifecycle, shutdown, startup
The ChromiumWebBrowser instance creates the underlying Chrom
exception error cefsharp, initialization, async, browser-lifecycle, timing
ChromiumWebBrowser
exception error cefsharp, disposal, objectdisposed, lifecycle
{settingName} now requires an absolute path, the path provid
exception error cefsharp, configuration, paths, absolute-path, validation
maxDegreeOfParallelism
exception error cefsharp, task-scheduler, argument-validation, concurrency
invalid or illegal characters used for binding property name
validation error cefsharp, javascript-binding, configuration, naming, validation
Please provide a valid mimeType
validation error cefsharp, resource-handler, legacy, argument-validation, mime
propertyInfo
validation error cefsharp, model-binding, reflection, argument-validation, null-reference
fieldInfo
validation error cefsharp, model-binding, reflection, argument-validation, null-reference
UnRegisterResourceHandler can only be used with the default
exception error cefsharp, resource-handler, configuration, extension-method
RequestContext is null, unable to obtain cookie manager
exception error cefsharp, cookies, lifecycle, initialization
Timeout greater than Maximum allowable value of 4294967295
validation error cefsharp, javascript, argument-validation, timeout
browser
validation error cefsharp, null-reference, argument-validation, lifecycle
IFrame instance is null. Browser has likely not finished ini
exception error cefsharp, frame, lifecycle, initialization
IBrowser instance is null. Browser has likely not finished i
exception error cefsharp, browser, lifecycle, null-reference
IBrowserHost instance is null. Browser has likely not finish
exception error cefsharp, browser-host, lifecycle, initialization
Unable to execute javascript at this time, scripts can only
exception error cefsharp, javascript, v8context, lifecycle