Mozilla has fixed issues causing Firefox to crash on macOS and get stuck with an unresponsive blank window when starting on Windows 11 systems.

According to the user who first reported the Windows freezing issue, the bug likely affects Firefox users running Windows 11 who also have this month’s cumulative update KB5023706 installed.

“When Firefox starts, it’s just a blank window (not a blank webpage) with just the min, max, [and] close the buttons. If I close the window, it says it’s not responding and sends a bug report to Microsoft”, the error report filed three days ago reads.

The accident report sent to Microsoft after Firefox process crash says the web browser “stopped responding and closed” because a “problem prevented this program from interacting with Windows”.

The user who reported the problem added that after uninstalling Windows update KB5023706, Firefox restarted as expected.

While the user report pinned the freezing issues on update KB5023706, it’s unclear if this was the source of the problem or if it just exacerbated a timing problem from a Changing behaviour making the profile available earlier during startup.

Mozilla has now fixed the browser startup hangs that trigger the freezing issue with the release of Firefox 111.0.1, the latest version released on Tuesday.

“Fixed a bug causing Firefox to hang on startup for some Windows users,” Mozilla explains in the Firefox 111.0.1 Release Notes.

Also fixes a macOS crash

Mozilla also fixed a second bug causing crashes when pinching zoom on macOS systems due to NativelayerCA invalid region checks.

“macOS users will experience crashes when pinching zoom in exceptional circumstances,” said Brad Werth, Mozilla Platform Engineer. explain when describing the impact of the issue a week ago after a fix was approved.

“This removes an intentional crash we put in place to weed out potential invalid pixels. We now believe those pixels are valid, so we don’t want this check anymore, and we certainly don’t need to crash.”

Although a bug report was first filed for this bug three years ago and labeled as “wontfix”, the number of accidents has increased exponentially from March 15 after the release of Firefox 111.0, which probably caused a fix.

“Fixed a crash on macOS when pinching zoom in certain circumstances,” Mozilla added in the Firefox 111.0.1 changelog.

Update: Revised story and title incorrectly linking Firefox Windows 11 crashing issue to KB5023706 update.