CefBrowserHost::CreateBrowser call failed when trying to reuse BrowserSettings instance

[PitySOFT]

• What version of the product are you using?

  • Nuget 71.0.0

• What architecture x86 or x64?

  • x86

• On what operating system?

  • Win 8 and Win10

• Are you using WinForms, WPF or OffScreen?

  • WPF with WindowsFormsHost

• What steps will reproduce the problem?

  • I have two instances of CefSharp with different CefSettings, because I can't change the settings on runtime. Depending on some data I choose what instance to show. Till version 71.0 the code where si make the swap between those two instances works great. But with version 71.0 it breaks with the exception attached below.

  • I try to set the Child of a WindowsFormsHost with an instance of a ChromiumWebBrowser with the following code MyFormsHost.Child = my ChromiumWebBrowser;

• What is the expected output? What do you see instead?

  • The application crashes because on unhandled exception.

• Please provide any additional information below.

  • System.InvalidOperationException
    HResult=0x80131509
    Message=CefBrowserHost::CreateBrowser call failed, review the CEF log file for more details.
    Source=CefSharp.Core
    StackTrace:
    at CefSharp.ManagedCefBrowserAdapter.CreateBrowser(IWindowInfo windowInfo, BrowserSettings browserSettings, RequestContext requestContext, String address) in c:\projects\cefsharp\cefsharp.core\managedcefbrowseradapter.cpp:line 29

  • The debug.log file is empty

• Does this problem also occur in the CEF Sample Application from.

  • The examples are not relevant to this because I used 2 instances of CefSharp

[amaitland]

Can you please fork https://github.com/cefsharp/CefSharp.MinimalExample and provide an example that reproduce your problem.

Using the WinForms version in a WPF app using WindowsFormsHost works as expected for me.

Without an example that actually reproduces your problem there is anything I can do.

[amaitland]

@PitySOFT Are you able to provide an example that reproduces your problem? I'll be releasing 71.0.1 bug fix packages in a few days, if you can provide an example in the next 48hrs I'll see if this is fixable, otherwise it'll have to wait for the next major release.

[PitySOFT]

Hi, didn't had time to make the example. I will come back with it when I'm ready to reproduce. Please release the 17.0.1 don't wait for me. Thanks.

[PitySOFT]

Hi,

I manage to reproduce the crash in a minimal project.

You have the project here.

Binary file removed

With Cef 69.0.0 will work fine, but using 71.0.0 will crash.

[merceyz]

No binary files, fork the minimal project instead and provide that as a link

[PitySOFT]

This is ok?

https://github.com/PitySOFT/CefSharp.MinimalExample

[merceyz]

Yes, thank you.

The issue is you're reusing the browser settings, the settings are disposed of after the browser is created at:

CefSharp/CefSharp.WinForms/ChromiumWebBrowser.cs

Lines 649 to 653 in 6f6ca94

	if (browserSettings != null)
	{
	browserSettings.Dispose();
	browserSettings = null;
	}

This was added in 4a41fdf for WinForms

[amaitland]

Reusing browser settings is problematic, so making them single use only.

Need an additional check and throw exception if they're disposed, will add that shortly..

Thanks for taking the time to reproduce 👍

[merceyz]

The OffScreen version already checks this[1], seems the check is missing for WPF and WinForms

1:

CefSharp/CefSharp.OffScreen/ChromiumWebBrowser.cs

Lines 382 to 385 in 6f6ca94

	else if(browserSettings.IsDisposed)
	{
	throw new ObjectDisposedException("browserSettings", "The BrowserSettings reference you have passed has already been disposed. You cannot reuse the BrowserSettings class");
	}

[amaitland]

Now that browser creation is common between WPF, informs and OffScreen checks can be made in

CefSharp/CefSharp.Core/ManagedCefBrowserAdapter.cpp

Line 26 in 6f6ca94

if (browserSettings == nullptr)

In WinForms it might make sense to remove the setter for browser settings.

Will provide full analysis for discussion when I am in front of a computer

[PitySOFT]

Thanks for information, I confirm that not using the same BrowserSettings works.

For the same example code I have some issues with onscreen keyboard for touch screens. I know that it's hard to test because the lack of the touch screens but maybe you can check something in the code.

On CefSharp 65.0.1 the keyboard works perfect, but:

• on 67.0.0 when the onscreen keyboard appears the sides of the keyboard are transparent but after a short period the sides becomes white.
• on 69.0.0 and 71.0.0 keyboard appears with transparent on sides, then this becomes white and then the keyboard will disappear.

I can provide videos for all situations.

[amaitland]

Any problems with the onscreen keyboard would need to be fixed in CEF/Chromium, see https://github.com/cefsharp/CefSharp/blob/master/CONTRIBUTING.md#cefsharp-vs-chromium-embedded-frameworkcef