[Problem/Bug]: Restart button on "Experiments Flags" page freezes WebView2 after changing a flag

[PCRacer]

What happened?

After changing a setting on the Experiments Flags page, a restart prompt appears to apply the new setting.

When clicking the blue Restart button in the bottom-right corner, the entire WebView2 instance freezes and becomes unresponsive. The canvas turns completely white, and the application stalls indefinitely instead of restarting.

Steps to Reproduce

1. Open the Experiments Flags page. { edge://flags/ }
2. Change any experimental flag.
3. Wait for the restart prompt to appear.
4. Click the blue Restart button in the bottom-right corner.

Expected Behavior

The WebView2 instance should restart normally and apply the updated experimental flag settings.

Actual Behavior

The WebView2 instance freezes completely, the canvas turns white, and the application becomes unresponsive without restarting.

Importance

Important. My app's user experience is significantly compromised.

Runtime Channel

Prerelease (Edge Canary/Dev/Beta)

Runtime Version

150.0.4078.65 -> 152.0.4154.0

SDK Version

1.0.4078.44

Framework

Win32

Operating System

Windows 10

OS Version

19045.6466

Repro steps

Steps to Reproduce

1. Open the Experiments Flags page. { edge://flags/ }
2. Change any experimental flag.
3. Wait for the restart prompt to appear.
4. Click the blue Restart button in the bottom-right corner.

Expected Behavior
The WebView2 instance should restart normally and apply the updated experimental flag settings.

Actual Behavior

The WebView2 instance freezes completely, the canvas turns white, and the application becomes unresponsive without restarting.

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Regression in newer Runtime

Last working version (if regression)

145.0.0.0

[anuragkumar878]

Hi @PCRacer , are you able to repro this on the wv2 sample app as well - https://github.com/MicrosoftEdge/WebView2Samples/tree/main/SampleApps/WebView2APISample ?
Also can you help us with a dump to identify why there seems to be a hang. More on this here - https://github.com/MicrosoftEdge/WebView2Feedback/blob/main/diagnostics/crash.md

[anuragkumar878]

Also please add a ProcessFailed event handler to your WebView2 control and log the output when clicking "Restart" on edge://flags and share with us. Official guide: https://learn.microsoft.com/en-us/microsoft-edge/webview2/concepts/process-related-events?tabs=dotnetcsharp

[PCRacer]

I don't have access to the sample app, but any Wv2 instance gives the same result when tested. I use the WebView2ForDelphi (WIN32) component suite.

This function worked very well before in our application using the wv2 control. It was only by accident when I tried to make some changes recently, when I noticed that when clicking on the restart button that the wv2 app freezes and stops and comes to a halt.

You can simply download our portable app and see for yourself:

Portable app:
https://github.com/PCRacer/SSuiteNetSurferPrometheus/releases/download/latest/SSuiteNetSurferPrometheusPortable32.zip

.

[PCRacer]

I don't have access to the sample app, but any Wv2 instance gives the same result when tested. I use the WebView2ForDelphi (WIN32) component suite.

This function worked very well before in our application using the wv2 control. It was only by accident when I tried to make some changes recently, when I noticed that when clicking on the restart button that the wv2 app freezes and stops and comes to a halt.

You can simply download our portable app and see for yourself:

Portable app:
https://github.com/PCRacer/SSuiteNetSurferPrometheus/releases/download/latest/SSuiteNetSurferPrometheusPortable32.zip

.

[anuragkumar878]

@PCRacer , thanks for sharing a sample app. Can you help me with where is the restart button in the app here. I was unable to find a way to trigger restart from the app you shared.
I clicked on refresh and restart netsurfer , and that seems to work fine. App was restarted without any freeze.

[PCRacer]

Open up the application and navigate to the following URL:

edge://flags/

Simply copy the link and right-click inside the edit box and select the "Paste and Go" option.

Type in the word "quic" in the edit box and set the option "enabled"

Steps to Reproduce

1. Open the Experiments Flags page. { edge://flags/ }
2. Change any experimental flag.
3. Wait for the restart prompt to appear.
4. Click the blue Restart button in the bottom-right corner.

The restart button will appear on the right-hand side at the bottom.

When you restart, the error will appear...

.