v146.0.70 JavaScript CefSharp object not availlable when loading via GET -> POST -> POST (iframe)

Is there an existing issue for this?

I have searched both open/closed issues, no issue already exists.

CefSharp Version

146.0.70

Operating System

Windows 11

Architecture

x64

.Net Version

.NET 10

Implementation

OffScreen

Reproduction Steps

The reproduction is quite involved that's why I created a separate repro https://github.com/campersau/CefSharp146BindObject

Expected behavior

CefSharp object should be available in iframe.

Actual behavior

CefSharp object is not available in iframe.

Regression?

Yes, worked in version 145.0.260 and before.

Known Workarounds

Not yet.

Does this problem also occur in the CEF Sample Application

Not Tested

Other information

The following error gets logged:

[61096:32296:0330/115323.606:ERROR:C:\projects\cefsharp\CefSharp.BrowserSubprocess.Core\CefAppUnmanagedWrapper.cpp:404] Failed to identify BrowserWrapper in OnContextCreated BrowserId:1

Possibly because of #5218

The reproduction is quite involved that's why I created a separate repro https://github.com/campersau/CefSharp146BindObject

Get a 404 when trying to open

Possibly because of #5218

Yes, it looks like it. Now the browserWrapper is required, before it wasn't even used to setup the bindings.

CefSharp/CefSharp.BrowserSubprocess.Core/CefAppUnmanagedWrapper.cpp

Lines 168 to 170 in 24e7df2

    
           auto browserWrapper = FindBrowserWrapper(browser->GetIdentifier()); 
        
           if (browserWrapper != nullptr && browserWrapper->JavascriptBindingApiEnabled && IsJavascriptBindingApiAllowed(browserWrapper, frame))

https://github.com/cefsharp/CefSharp/pull/5218/changes#diff-357680293df8761a33d94272a6a9faaa1528bb062412c8d3893de9ba94e030a5R168-R170

https://github.com/cefsharp/CefSharp/pull/5218/changes#diff-357680293df8761a33d94272a6a9faaa1528bb062412c8d3893de9ba94e030a5L154

I debugged this a bit with https://ci.appveyor.com/project/campersau/cefsharp/build/artifacts to see when browserwrappers are added / removed. And this is the log:

INDEX PAGE
[87396:13172:0331/110222.002:ERROR:C:\projects\cefsharp\CefSharp.BrowserSubprocess.Core\CefAppUnmanagedWrapper.cpp:68] Added BrowserWrapper in OnBrowserCreated BrowserId: 1 Added: True
[87396:13172:0331/110222.247:ERROR:C:\projects\cefsharp\CefSharp.BrowserSubprocess.Core\CefAppUnmanagedWrapper.cpp:68] Added BrowserWrapper in OnBrowserCreated BrowserId: 1 Added: False
FORM POST SUBMIT
[87396:13172:0331/110222.301:ERROR:C:\projects\cefsharp\CefSharp.BrowserSubprocess.Core\CefAppUnmanagedWrapper.cpp:140] Removed BrowserWrapper in OnBrowserDestroyed BrowserId: 1
FORM POST SUBMIT IFRAME
[87396:13172:0331/110222.594:ERROR:C:\projects\cefsharp\CefSharp.BrowserSubprocess.Core\CefAppUnmanagedWrapper.cpp:420] Failed to identify BrowserWrapper in OnContextCreated BrowserId: 1

The browser is tried to be added twice and then removed once.
When submitting via POST the browser gets destroyed (no other browser gets created though), and then it isn't found anymore.

When submitting via POST the browser gets destroyed (no other browser gets created though), and then it isn't found anymore.

Sounds like a bug in CEF. Any chance you could test with the --disable-request-handling-for-testing command line arg to see if CEF's request interceptor is part of the problem.

Same output with

cefsettings.CefCommandLineArgs.Add("disable-request-handling-for-testing");

Thanks for testing.

FYI: I tested it with 147 (campersau@9f8c038) again and the issue is still there.
I guess it was there previously but we haven't noticed it until #5218

I think it's relatively recent as there are reports of issues with the WCF channel being disposed starting in 145

#5232
#5233

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v146.0.70 JavaScript CefSharp object not availlable when loading via GET -> POST -> POST (iframe) #5228

Is there an existing issue for this?

CefSharp Version

Operating System

Architecture

.Net Version

Implementation

Reproduction Steps

Expected behavior

Actual behavior

Regression?

Known Workarounds

Does this problem also occur in the CEF Sample Application

Other information

Metadata

Assignees

Labels

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	auto browserWrapper = FindBrowserWrapper(browser->GetIdentifier());

	if (browserWrapper != nullptr && browserWrapper->JavascriptBindingApiEnabled && IsJavascriptBindingApiAllowed(browserWrapper, frame))

v146.0.70 JavaScript CefSharp object not availlable when loading via GET -> POST -> POST (iframe) #5228

Description

Is there an existing issue for this?

CefSharp Version

Operating System

Architecture

.Net Version

Implementation

Reproduction Steps

Expected behavior

Actual behavior

Regression?

Known Workarounds

Does this problem also occur in the CEF Sample Application

Other information

Activity

amaitland commented on Mar 31, 2026

amaitland commented on Mar 31, 2026

campersau commented on Mar 31, 2026

campersau commented on Mar 31, 2026

amaitland commented on Mar 31, 2026

campersau commented on Mar 31, 2026

amaitland commented on Mar 31, 2026

campersau commented on May 5, 2026

amaitland commented on May 6, 2026

Metadata

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Development

Issue actions