[Bug]: macOS 27 beta 7 — client 34.0.3 crashes during account setup in QQuickAccessibleAttached::setRole

[JensKamella]

⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on GitHub. I searched for the exact crash symbol, macOS version, and build number. The existing macOS 27 issue Invisible checkmarks for folders in Classic sync on Mac OS 27 beta #10282 concerns invisible checkmarks and is unrelated.
• Nextcloud Server and Desktop Client are up to date.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Nextcloud Desktop 34.0.3 consistently crashes during first-time account setup on macOS 27.0 beta 7. The crash happens immediately after entering a valid HTTPS Nextcloud server URL and continuing. The server's status.php request succeeds, then the client terminates with EXC_BAD_ACCESS / SIGSEGV.

The fault is on the main thread in QtQuick accessibility handling:

QQuickAccessibleAttached::setRole(QAccessible::Role)
QtQuickTemplates2
QtGui
QPlatformAccessibility::setActive(bool)
libqcocoa.dylib
AppKit -[NSWindow(NSWindowAccessibility) accessibilityFocusedUIElement]
AppKit NSAccessibilityHandleFocusChangedForce
AppKit -[NSWindow _realMakeFirstResponder:]
libqcocoa.dylib
QWindowPrivate::destroy()
QQuickWindowQmlImpl::~QQuickWindowQmlImpl()
QQuickPopup::~QQuickPopup()
QQuickMenu::~QQuickMenu()

This is not fixed by 34.0.3. Eight local macOS crash reports show the identical top frame and signal across three client versions/builds:

• 34.0.50 test build: 3 crashes
• 34.0.2: 4 crashes
• 34.0.3: 1 crash

Every report has:

Exception: EXC_BAD_ACCESS
Signal: SIGSEGV
Faulting thread: main thread
Top frame: QtQuick QQuickAccessibleAttached::setRole(QAccessible::Role)

Steps to reproduce

1. Use macOS 27.0 beta 7 (build 26A5421a) on Apple Silicon.
2. Install the official Nextcloud Desktop Client 34.0.3 package for macOS 13 and later.
3. Launch Nextcloud with no configured accounts.
4. In the setup wizard, enter a valid HTTPS URL for a reachable Nextcloud server.
5. Continue to the authentication step.
6. Observe that the client crashes immediately with SIGSEGV.

The issue reproduced repeatedly with 34.0.2 and an earlier 34.0.50 test build as well.

Expected behavior

The setup wizard should continue to the authentication flow and the client should remain running.

Which files are affected by this bug

None. The crash occurs during initial account setup before synchronization is configured.

Operating system

macOS

Which version of the operating system are you running?

macOS 27.0 beta 7 (26A5421a)

Hardware

• Model: Mac14,9
• Architecture: arm64

Installation method

Official Installer for macOS 13 and later, followed by the built-in Sparkle update from 34.0.2 to 34.0.3.

The installed 34.0.3 application passes both checks:

codesign --verify --deep --strict: valid
spctl: accepted
source=Notarized Developer ID
origin=Developer ID Application: Nextcloud GmbH (NKUJUXUJ3B)

Nextcloud Server version

34.0.2

The server responds normally to status.php and reports no maintenance mode or pending database upgrade. The client log records QNetworkReply::NoError for this request.

Nextcloud Desktop Client version

Nextcloud version 34.0.3
Git revision 7563f574a87883f8aa4c42454f795dc9a9c56ca8
Using Qt 6.10.2, built against Qt 6.10.2
Using Qt platform plugin 'cocoa'
Using OpenSSL 3.6.3
Running on macOS 27.0, arm64

Did this occur after an update or on a clean installation?

Both. The same crash occurred after clean/manual installations of 34.0.2 and a 34.0.50 test build, and again after the automatic update to 34.0.3.

Are you using the Nextcloud Server Encryption module?

No.

Are you using an external user backend?

• Default internal user backend
• LDAP or Active Directory
• SSO / SAML
• Other

Nextcloud Server logs

No relevant server error. The crash is client-side and occurs after the server availability check succeeds, before authentication completes.

Additional information

Sanitized client events immediately before the crash:

Config accounts version: 13
No accounts were migrated, prompting user to set up accounts and folders from scratch.
No file provider domains found.
Starting setup wizard.
FinderSync broker is reachable; the extension can connect.
status.php returns installed=true, maintenance=false, version=34.0.2; QNetworkReply::NoError
Server requested authentication and no user was provided.
Unknown WWW-Authenticate reply to auth-test PROPFIND: basic realm="nextcloud", charset="utf-8"
[process terminates with SIGSEGV in QQuickAccessibleAttached::setRole]

The 34.0.3 release notes include other File Provider and signing fixes, but the crash described here remains unchanged from 34.0.2.

A full Apple .ips report and Nextcloud client log are available privately if maintainers need them; they were not attached publicly because they contain local machine paths and installation metadata.

[Rello]

Hello @JensKamella

can you send us the ips here https://cloud.nextcloud.com/s/X924rP7ZXBDXKHG