Launching multiple WebView2 instances in different builds of the same application does not work

[janbalcarik]

We are using WebView2 with a fixed userDataFolder setting. Sometimes, we need to run different versions of our application. In some cases, this leads to an error that prevents the second application instance (with a different version) from starting. This issue does not always occur, but one specific case where the second instance never starts is when the CoreWebView2EnvironmentOptions.Language setting is changed.

I assume that, for some reason, WebView2 determines that a new process must be started separately, meaning it does not reuse the already running process. Since the userDataFolder is already locked by the first WebView2 instance, the second one fails to start.

Is there any way to check exactly how WebView2 determines whether a completely new instance is required? Or am I misunderstanding how the startup process works? Could you please clarify this?

Thank you.