Error while fulfilling of JS: Request BrowserId : 1 not found it's likely the browser is already closed

[CloudMak]

Is there an existing issue for this?

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

CefSharp Version

117.2.40

Operating System

Windows 10

Architecture

x64

.Net Version

.net 6.0

Implementation

OffScreen

Reproduction Steps

Version: Above 108

Steps:
Create instance of CefSharp.OffScreen.ChromiumWebBrowser
br = CefSharp.OffScreen.ChromiumWebBrowser();

Go by url 2 times:
br.Load(url)
await br.EvaluateScriptAsPromiseAsync(script);
br.Load(url)
await br.GetSourceAsync();
br.Load(url)

Fulfill JS
_browser.EvaluateScriptAsPromiseAsync(script)

Expected behavior

Fulfilling of JS

Actual behavior

JS Error Request BrowserId : 1 not found it's likely the browser is already closed

Regression?

After regression to version 108 problem dissapeared.

Known Workarounds

Likely problem is here
https://github.com/cefsharp/CefSharp/blob/master/CefSharp.BrowserSubprocess.Core/CefAppUnmanagedWrapper.cpp
Look at history..

Does this problem also occur in the CEF Sample Application

Yes using WPF/OffScreen command line args

Other information

No response

[amaitland]

Reproduction Steps

Version: Above 108

Please create a Unit test that reliably reproduces the problem and submit a PR.

https://github.com/cefsharp/CefSharp/tree/master/CefSharp.Test

Your code is incomplete and not enough for me to investigate this.

Likely problem is here
https://github.com/cefsharp/CefSharp/blob/master/CefSharp.BrowserSubprocess.Core/CefAppUnmanagedWrapper.cpp
Look at history..

What is the problem exactly? Please provide details of your analysis.

Just saying look at history is meaningless. If you can see a specific error that needs fixing then submit a PR.

Likely this is the result of upstream changes to CEF/Chromium.

[CloudMak]

Reproduction Steps

Version: Above 108

Please create a Unit test that reliably reproduces the problem and submit a PR.

https://github.com/cefsharp/CefSharp/tree/master/CefSharp.Test

Your code is incomplete and not enough for me to investigate this.

Likely problem is here
https://github.com/cefsharp/CefSharp/blob/master/CefSharp.BrowserSubprocess.Core/CefAppUnmanagedWrapper.cpp
Look at history..

What is the problem exactly? Please provide details of your analysis.

Just saying look at history is meaningless. If you can see a specific error that needs fixing then submit a PR.

Likely this is the result of upstream changes to CEF/Chromium.

bro, are you interesting in solution of error of your project?
If you have concrete questions - ask me. I don't see any concrete questions. Looks like you just don't want to solve the problem.

Exactly, problem is in Error while fulfilling JS.
You see last call of _browser.EvaluateScriptAsPromiseAsync(script) entails error.

[amaitland]

Likely problem is here
https://github.com/cefsharp/CefSharp/blob/master/CefSharp.BrowserSubprocess.Core/CefAppUnmanagedWrapper.cpp
Look at history..

What is the problem exactly? Please provide details of your analysis.

I don't see a problem, so I need more information.

You see last call of _browser.EvaluateScriptAsPromiseAsync(script) entails error.

I need a reliable means to reproduce the problem. The best way to achieve that is to provide a failing test case.

bro, are you interesting in solution of error of your project?

There's a high change this is a change in CEF/Chromium and will need to be addressed upstream.

I don't see any concrete questions. Looks like you just don't want to solve the problem.

I'm very busy. If you want my assistance then you need to provide sufficient information. Just saying look at history is entirely pointless. Link to the exact commit that you think introduced the problem and provide an analysis of where you think the problem is.

[amaitland]

CefSharp/CefSharp.Test/Javascript/EvaluateScriptAsyncGenericTests.cs

Line 137 in bb30e23

public async Task ShouldLoadGoogleAndEvaluateScript()

There are a number of unit tests that could be used as a base for reproducing this issue. Above is one such example.

If someone can create a test that reliability reproduces the issue, please create a pull request. Then I can have a look to see what's going on.

[daveime68]

This is still an issue as of 119.4.30 Core.

Once a web page has been loaded, and any automated action instigated on that page, for example clicking on a link, clicking a submit button, in fact ANYTHING that causes a new page to load in it's place, then any subsequent EvaluateScriptAsPromiseAsync or EvaluateScriptAsync executed on the new page will fail with the error message "Request BrowserId : 1 not found it's likely the browser is already closed".

As others have pointed out, the issue seems to be here:

https://github.com/cefsharp/CefSharp/blob/master/CefSharp.BrowserSubprocess.Core/CefAppUnmanagedWrapper.cpp

function OnProcessMessageReceived

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

is returning a nullptr, which triggers the error message.

But if you prefer to just respond with snarky comments or complain that no one will make a unit test for you, when the issue has been clearly described by multiple users, then honestly that's a you problem.

I'd imagine most people just pull packages via NuGet, and when they identify a problem and report it, it's on you as the maintainer to address it. No one else is obliged to make unit tests for you, or delve into the inner workings of C# wrappers to a C++ interface to a 3rd party chromium library.

Until then, your project will remain fundamentally broken.

[ficho-hun]

It seems that happening with only some Websites.
I enabled the CEF logging, maybe can you find here something.

cef.log

[netmaxik]

good day @amaitland
I did https://github.com/netmaxik/CefSharp.MinimalExample.netcore special.
Use WPF project and press Test button. On title you will see Elements under mouse. Press Test again to stop. After you go to : https://accounts.google.com/?hl=en, wait to load and press test again you see that error appears . For me last version where it was work correctly was : 112.3.0 After that i got that error everywhere.

[nebojsasandin]

@netmaxik have you tried the new v121.3.x ? Has the issue been resolved @amaitland ?
I'm experiencing the same problem @netmaxik is, basically anything related to Google (google drive, docs, gmail, accounts, etc...) is broken on all versions past 112.3.0. Haven't tested v121.3.x though.

[amaitland]

There's a high change this is a change in CEF/Chromium and will need to be addressed upstream.

As above.

If someone can create a test that reliability reproduces the issue, please create a pull request. Then I can have a look to see what's going on.

When someone creates a unit test then I'll have another look.

Your asking for my time. I'm asking for for the community to contribute their time. It's a simple ask.

---

MAKE SURE you are waiting for the page to load correctly before executing javascript.

br.Load(url)
await br.EvaluateScriptAsPromiseAsync(script);

Calling Load then immediately evaluating javascript isn't reliable. You never know which V8 context the javascript will be executed in. If you perform a cross origin navigation then it's likely even more problematic.

await br.LoadAsync(url)
await br.EvaluateScriptAsPromiseAsync(script);

Waits for the page to load.

---

You can try disabling site isolation trivls to see if the behaviour changes.

settings.CefCommandLineArgs.Add("disable-site-isolation-trials");

[nebojsasandin]

@amaitland Thank you for your reply.

"disable-site-isolation-trials" did not help.

Here's the simplest test I could compile: https://github.com/nebojsasandin/ceftest

And it isn't much more complicated than few lines, so it can even fit into this comment here:

    using (var browser = new ChromiumWebBrowser("https://www.google.com/"))
    {
        browser.WaitForInitialLoadAsync().Wait();
        browser.Load("https://accounts.google.com/");
        browser.WaitForNavigationAsync().Wait();
        var rez = browser.GetMainFrame().EvaluateScriptAsync<string>("(function() {  return document.querySelector(\"button[aria-haspopup='menu']\").innerText; })();").Result;
    }

It is expected from this script to return "Create Account" text from the querySelector button, but what happens is the crash with the Request BrowserId : 1 not found it's likely the browser is already closed inner exception.

If the original url is: about:blank, https://accounts.google.com, https://www.yahoo.com, https://www.bing.com, etc.... it all works fine.
The point where it breaks is if the original url is: https://www.google.com, and then it navigates to https://accounts.google.com/
This is why it was so hard to catch it. I haven't found another instance of this problem. Only when Google is being used.
Also, Script Execution, without any return values, works just fine, and produces no exceptions.

[amaitland]

@nebojsasandin Thanks. You can create a test which mimics your example in

CefSharp/CefSharp.Test/OffScreen/OffScreenBrowserTests.cs

Line 31 in bb30e23

public async Task ShouldWorkWhenLoadingGoogle()

Please create a unit test inside the CefSharp.Test project and submit a PR.

---

If the original url is: about:blank, https://accounts.google.com, https://www.yahoo.com, https://www.bing.com, etc.... it all works fine.
The point where it breaks is if the original url is: https://www.google.com, and then it navigates to https://accounts.google.com/
This is why it was so hard to catch it. I haven't found another instance of this problem. Only when Google is being used.
Also, Script Execution, without any return values, works just fine, and produces no exceptions.

What you are describing sounds like an upstream issue.

---

You are using the async API in a sync fashion which is not supported.

There's an async example available at https://github.com/cefsharp/CefSharp.MinimalExample/blob/master/CefSharp.MinimalExample.OffScreen/Program.cs#L48 which you can use as a reference.

[nebojsasandin]

Not sure if this was what I was supposed to do (I've never done this before), but I forked the entire master branch, changed the offscreen test cs file, included the part which causes an exception, and initialized pull request on this one single file from my fork: #4741

I could not get it to compile or run though, there was a whole bunch of errors in the C++ sources which I'm unfamiliar with, so I could not see if the test truly replicates the issue described here, but I did test it in async fashion as well in the original test I sent you, and it did produce the same exception, so hopefully you'll be able to replicate the issue on your end and see what's causing it in the first place, so we can get this resolved.

Thank you.