EXC_BAD_ACCESS (SIGSEGV) crash during the window creation phase usually indicates an OS-level compatibility conflict rather than a corrupted installation on your individual Mac. Because macOS 27.0 (Golden Gate) was just released, it has introduced several graphical and window-management bugs (such as known issues with WindowServer, Mission Control, and AppKit window rendering).
Since JW Library on Apple Silicon runs via Mac Catalyst (the iPadOS app wrapper), changes in how macOS 27 handles UIKit-to-AppKit window scene creation are likely triggering memory access violations.
Steps to take:
Force-Bypass Saved State Corruption
Sometimes apps crash on launch because macOS is attempting to restore a corrupted window state from a previous session.
- Close all app processes.
- Hold down the Shift key and click the JW Library icon to launch it.
- Why: This tells macOS to bypass the saved state database and open a completely fresh window template.
Isolate the Window Environment in Safe Mode
To rule out any third-party background utilities (like window organizers, custom cursor managers, or stage managers) that hook into window creation and conflict with macOS 27:
Clear App Containers (While Preserving Data)
If the crash is tied to a broken database interaction during launch, resetting the container folder can help:
- Open Finder and press Cmd + Shift + G.
- Paste the following path: ~/Library/Containers/
- Look for the folder associated with JW Library (it usually contains com.jw.jwlibrary or just JW Library).
- Move this folder to your Desktop (do not delete it yet, as it contains your downloaded publications and personal notes).
- Relaunch the app to see if a clean window environment initializes.
If the app continues to crash in Safe Mode even with a cleared container, the issue is an absolute incompatibility between JW Library 15.9.1 and the macOS 27.0 build (26A428). In this case, your best path forward is to submit the crash log directly to the developers through the App Store feedback mechanisms so they can address the AppKit rendering changes in an upcoming version.
