Dockable dialogues disabled on Windows menu

Environment/Versions

• GIMP version: 3.0.0-RC1
• Package: Installer from gimp.org
• Operating System: macOS Sequoia 15.0.1

Description of the bug

All 'Windows>Dockable Dialogues' are disabled

Reproduction

Is the bug reproducible? Always

Reproduction steps:

1. Open GIMP
2. Go to Windows>Dockable Dialogues

…

Expected result: Menu items are enabled to allow selection of a dockable dialogue to open

Actual result: All menu items are disabled

Additional information

All the dockable dialogues are enabled if accessed via 'Add Tab' on the 'Configure this tab' button