Custom NSWindow styleMask behavior changed/broken resulting in unresizable or non-responsive windows in macOS Tahoe 26.3 RC

Question

Created 3h

Replies 3

Boosts 2

Participants 2

NSWindow objects with custom styleMask configurations seem to behave erratically in macOS Tahoe 26.3 RC.

For example an NSWindow is not resizable after issuing .styleMask.remove(.titled) or some NSWindow-s become totally unresponsive (the NSWindow becomes transparent to mouse events) with custom styleMask-s.

This is a radical change compared to how all previous macOS versions or the 26.3 beta3 worked and seriously affects apps that might use custom NSWindows - this includes some system utilities, OSD/HUD apps etc, actually breaking some apps.

Such fundamental compatibility altering changes should not be introduced in an RC stage (if this is intentional and not a bug) imho.

Boost

Answer 1

Steve4442 OP

3h

FB21879057

0

Answer 2

Frameworks Engineer OP

Apple

1h

Hi Steve,

Thanks for the Feedback number. We've gotten a few similar reports on 26.3 RC and are investigating.

1

Answer 3

Steve4442 OP

1h

I am super relieved it's not only me hallucinating all this and others encountered this as well. :)

I narrowed down the issue to .styleMask.remove(.titled). Depending on other styleMask flags and NSWindow properties, this can result in (1) an inability to resize the window or (2) a kind of click-thru effect - the content does not seem to capture mouse events but the window acts as if it would be transparent to user interaction.

0