[SOLVED] Apps show white windows or crash after update – OpenDyslexic WOFF / Fontconfig / WebKitGTK

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1

I want to share a solution to a problem that took quite a bit of debugging,
because it may affect other Zorin OS users after recent updates.

SYSTEM

Zorin OS 18.1
GNOME
AMD Radeon RX 580 / amdgpu
Mesa 25.2.8
WebKitGTK 2.52.6

SYMPTOMS

After an update, several applications stopped working correctly:

  • Proton Authenticator opened, but its content area was completely white.
  • Aloha Browser crashed / failed to render pages.
  • A minimal GTK3 + WebKitGTK test also showed only a white WebView.

At first this looked like a GPU, Mesa, Wayland or amdgpu problem.

We tested:

  • Wayland and Xorg
  • different kernels
  • GPU acceleration
  • software rendering
  • WebKit DMABUF disabled
  • WebKit compositing disabled
  • WebKit sandbox disabled
  • GNOME extensions
  • /dev/dri permissions
  • WebKit package integrity

None of these fixed the problem.

ROOT CAUSE / IMPORTANT CLUE

Running:

fc-list | grep -Ei '.(woff|woff2)(:|$)'

showed:

/usr/share/fonts/woff/opendyslexic/OpenDyslexic-Bold.woff
/usr/share/fonts/woff/opendyslexic/OpenDyslexic-Italic.woff
/usr/share/fonts/woff/opendyslexic/OpenDyslexic-BoldItalic.woff
/usr/share/fonts/woff/opendyslexic/OpenDyslexic-Regular.woff

More importantly:

fc-match -v

showed that Fontconfig was actually selecting:

file: "/usr/share/fonts/woff/opendyslexic/OpenDyslexic-Bold.woff"
fontwrapper: "WOFF"

WORKAROUND

Instead of deleting fonts or downgrading WebKitGTK, I excluded WOFF/WOFF2
fonts from Fontconfig for my user account.

mkdir -p ~/.config/fontconfig/conf.d

cat > ~/.config/fontconfig/conf.d/99-disable-woff.conf <<'EOF'

<?xml version="1.0"?> *.woff *.woff2 EOF

Then rebuild the Fontconfig cache:

fc-cache -f -v

Verification:

fc-list | grep -Ei '.(woff|woff2)(:|$)'

After applying this workaround:

  • Minimal WebKitGTK test rendered normally.
  • Proton Authenticator rendered normally again.
  • Aloha Browser also worked normally again.
  • After a complete reboot, all affected applications continued to work.

ROLLBACK

The workaround is easy to undo:

rm ~/.config/fontconfig/conf.d/99-disable-woff.conf
fc-cache -f -v

No system fonts were deleted and no WebKitGTK/Mesa packages were downgraded.

UPSTREAM

This appears to be related to WebKit bug 325185:
"[GTK][WPE][Skia] Web process spins at 100% CPU forever in
SkFontMgr_fontconfig GetFamilyNames() when fontconfig lists a font
without a family."

NOTE ABOUT ALOHA

Aloha showed a Blink/Chromium crash involving:

RemoteFontFaceSource::CreateLoadingFallbackFontData()

The same Fontconfig WOFF workaround also fixed Aloha on this machine.

I cannot say whether the Aloha/Blink issue has exactly the same upstream
root cause as WebKit bug 325185, only that both problems disappeared
after excluding the WOFF fonts from Fontconfig.

I hope this saves someone else from spending hours debugging GPU drivers,
Mesa, Wayland and kernels.

1 Like
2

Thank you so much. The steps you listed worked for me. It was frustrating that one by one apps were failing to open.