Microsoft Edge 154.0.4258.37 freezes on Ubuntu when pressing Space in text fields — possible fontconfig cache-12 regression

Summary

After upgrading Microsoft Edge Stable from 153.0.4234.48 to 154.0.4258.37 on Ubuntu 24.04, Edge started freezing reproducibly while entering text.

The browser initially works normally for a few seconds after startup. Typing text without spaces can continue working for a long time. However, after Edge has been running for several seconds, pressing Space inside a text field can freeze the entire Edge UI.

The application then becomes unusable and has to be closed.

This behavior started only after the upgrade to Edge 154.

There is evidence on the affected system that Edge/Chromium 154 is also writing a newer fontconfig cache format into the shared user font cache, including cache-12 files and compatibility symlinks from older cache versions.

This may be related to the Chromium 154 fontconfig cache regression tracked upstream.

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Environment

Operating system

Ubuntu 24.04.5 LTS
Codename: noble

Desktop

GNOME
XDG_SESSION_TYPE=wayland
XDG_CURRENT_DESKTOP=ubuntu:GNOME
WAYLAND_DISPLAY=wayland-0

Microsoft Edge

Microsoft Edge 154.0.4258.37
Package: microsoft-edge-stable 154.0.4258.37-1

Previous working version:

Microsoft Edge 153.0.4234.48

Upgrade occurred on:

2026-09-25
153.0.4234.48-1 -> 154.0.4258.37-1

Fontconfig

fontconfig 2.15.0-1.1ubuntu2
libfontconfig1 2.15.0-1.1ubuntu2

Graphics

Intel TigerLake-LP GT2 / Iris Xe Graphics
Kernel driver: i915

Kernel

Linux 7.0.0-34-generic
Ubuntu 24.04

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Steps to reproduce

Start Microsoft Edge Stable 154.0.4258.37 normally on Ubuntu GNOME/Wayland.

Open a webpage containing a normal text input, textarea, chat input, or other editable field.

Wait several seconds after Edge startup.

Start typing text.

Text without spaces may continue working normally.

Press the Space key while entering a sentence.

Actual result

The Microsoft Edge UI freezes.

The browser stops responding and must be closed.

The issue is highly correlated with inserting whitespace into editable text after Edge has been running for a short period.

Expected result

Pressing Space in an editable field should behave normally and must not freeze the browser.

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Regression information

This problem was not observed with:

Microsoft Edge 153.0.4234.48

It appeared after upgrading to:

Microsoft Edge 154.0.4258.37

No intentional browser configuration change accompanied the upgrade.

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Fontconfig evidence

The affected machine uses system fontconfig:

fontconfig 2.15.0

The user's shared font cache currently contains files such as:

*-le64.cache-12

and many compatibility symlinks such as:

*-le64.cache-9  -> *-le64.cache-12
*-le64.cache-10 -> *-le64.cache-12
*-le64.cache-11 -> *-le64.cache-12

Examples observed on the affected system:

32b6488e5b8292a2e95c79d947e009e8-le64.cache-9
 -> 32b6488e5b8292a2e95c79d947e009e8-le64.cache-12

32b6488e5b8292a2e95c79d947e009e8-le64.cache-10
 -> 32b6488e5b8292a2e95c79d947e009e8-le64.cache-12

32b6488e5b8292a2e95c79d947e009e8-le64.cache-11
 -> 32b6488e5b8292a2e95c79d947e009e8-le64.cache-12

The cache-12 files on this machine were generated after the Edge 154 upgrade.

This looks potentially related to the Chromium 154 regression involving bundled fontconfig writing newer cache files into the shared:

~/.cache/fontconfig/

and creating compatibility symlinks for older cache formats.

Possibly related upstream Chromium issue:

Chromium issue 565132857

A duplicate report describing the cache-12 / cache-9 compatibility symlink behavior is:

Chromium issue 565475896

Please verify whether Microsoft Edge 154 includes the affected Chromium/fontconfig change and whether the Chromium fix needs to be incorporated into an Edge Stable update.

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Additional Edge log observation

The Edge GPU process also logs:

ERROR:ui/ozone/platform/wayland/gpu/wayland_surface_factory.cc:249
'--ozone-platform=wayland' is not compatible with Vulkan.
Consider switching to '--ozone-platform=x11' or disabling Vulkan

This may be a separate Wayland/Vulkan issue, but I am including it because it appears consistently during Edge startup on the affected machine.

The very specific trigger involving text entry and Space, together with the fontconfig cache state, makes the fontconfig/Chromium 154 regression a stronger candidate for the primary cause.

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Other observations

There is no obvious Edge core dump associated with the freeze.

The issue affects the browser UI rather than only one specific website.

The strongest reproduction characteristic is:

Edge starts
-> initially works
-> wait several seconds
-> enter text
-> press Space
-> browser freezes

Typing characters without spaces can remain functional much longer.

This makes the issue particularly disruptive because ordinary text entry, search, forms, chat applications, and web-based editors become unusable.

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System font cache state

The following pattern is present extensively in:

~/.cache/fontconfig/

cache-9  -> cache-12
cache-10 -> cache-12
cache-11 -> cache-12

The system fontconfig version is 2.15.0.

Because the browser is using a shared user-level font cache, a bundled fontconfig implementation writing a newer cache format there may affect both Edge itself and other desktop applications.

A browser-private font cache or an Edge-specific XDG_CACHE_HOME appears to be a possible temporary mitigation, but no permanent workaround has been applied yet on this machine so that the original failure state remains available for investigation.

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Impact

Severity from the user's perspective is high.

Normal browsing may initially appear functional, but any workflow requiring sentence entry can freeze the browser.

Examples include:

search fields;

web forms;

chat interfaces;

GitHub text fields;

editors;

messaging applications.

This effectively makes Edge 154 unusable as a primary browser on the affected Ubuntu system.

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Request

Please investigate whether Edge Stable 154.0.4258.37 for Linux contains the Chromium/fontconfig regression associated with incompatible shared font caches.

In particular, please check:

Whether Edge's bundled fontconfig writes cache-12 files into the system user's shared ~/.cache/fontconfig directory.

Whether it creates cache-9, cache-10, and cache-11 symlinks pointing to those cache-12 files.

Whether text shaping triggered during editable text entry can enter a crash, hang, or CPU loop when the host fontconfig is version 2.15.0.

Whether Chromium issue 565132857 and its fix apply directly to Microsoft Edge 154.

Whether the fix can be backported or released through the Edge Stable Linux channel.

I can provide additional logs, filesystem state, package information, or perform controlled tests on the affected Ubuntu machine if needed.