[Bug]: Bad WebBrowserComponent behavior in FL Studio on macOS

[colinsullivan]

Detailed steps on how to reproduce the bug

Here are some details on issues I am seeing on newer macOS versions on FL 2025, when building DAW plugins with a webview. I am currently able to repro on macOS Sequoia 15 , FL 2025.

Here is a simple JUCE 8 webview application which prints some text to the console when the document “mouseout” event occurs. Building this for VST3 or AU on a mac can be used to reproduce the issues.

juce-webview-simple: document-mouseout

Issue 1: Document “pointerout” behavior

In other DAWs , the document mouseout & pointerout behavior is consistent with a web browser window. When the mouse exits the window, this callback occurs.

When the VST is used in FL 2025 , it seems there are intermittent “dead spots” where this callback does not occur when the mouse exits the plugin boundary.

Repro steps:

• Compile VST3 or AU from the document-mouseout branch
• Load the plugin on a track in FL Studio 25
• Right-click -> inspect and view the console tab
• Mouse around the edge of the window, note the dead spots which do not print anything to the console. This may depend on the position of the plugin window within FL Studio 25

Issue 2: Tab causes webview to blank

Pressing tab in FL navigates between panes in the UI, bringing the plugin to the “background” then to the foreground again. Doing this repeatedly appears to cause the native web view instance to be destroyed and re-created. Sometimes this reloads the same URL that was loaded previously, but eventually it gets stuck loading about:blank - this is the default URL that a new Webview instance loads, which is part of my suspicion that something is being destroyed and re-created.

Repo steps:

• Compile VST3 or AU from the document-mouseout branch
• Load the plugin on a track in FL Studio 25
• Right-click -> inspect and view the network tab
• Focus the plugin window and press tab repeatedly
• Note FL Studio 25 behavior to cycle through windows, note web view goes blank, note web inspector shows the web view has loaded "about:blank"

What is the expected behaviour?

Pressing tab repeatedly in FL Studio 25 does not cause the WebBrowserComponent to load about:blank and turn into a white screen.

Mouse events from the web gui work as expected

Operating systems

macOS

What versions of the operating systems?

I am seeing on newer macOS versions on FL 2025, when building DAW plugins with a webview. I am currently able to repro on macOS Sequoia 15 , FL 2025.

Architectures

Arm64/aarch64

Stacktrace

Plug-in formats (if applicable)

VST3, AU

Plug-in host applications (DAWs) (if applicable)

FL 2025

Testing on the develop branch

The bug is present on the develop branch

Code of Conduct

• I agree to follow the Code of Conduct

[Moebytes]

FL Studio wants the .withKeepPageLoadedWhenBrowserIsHidden() option, or it randomly becomes a blank page when opening and closing the plugin. For some reason, the default is to replace it with a blank page when it's hidden and it's not being restored correctly. That will probably also fix the tab behavior