Description:
Following a recent update, launching native COSMIC applications (such as cosmic-files) results in spawned windows that are completely frozen and unresponsive to interaction.
Upon checking the system journal, it appears that xdg-desktop-portal-cosmic is encountering a fatal protocol error regarding cosmic_corner_radius_layer_v1 and completely terminating the Wayland thread. Because the portal crashes, the spawned application windows become orphaned UI zombies.
Steps to Reproduce:
- Open a terminal.
- Launch a native app (e.g., cosmic-files).
- The app spawns a window, but it is completely unresponsive (cannot be moved, clicked, or closed normally).
- Check journalctl, which reveals a portal crash.
Actual Behavior / Logs:
The terminal running the app displays missing theme keys warnings (e.g., list_button), but the actual fatal crash occurs in the background daemon.
From journalctl[cite: 1]:
aoû 16 14:27:35 pop-os xdg-desktop-portal-cosmic[3771]: cosmic_corner_radius_layer_v1#186: error 1: CosmicCornerRadiusLayerV1 { ... } corner radius too large
...
2026-08-16T12:27:35.949660Z ERROR panic: thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: Backend(Protocol(ProtocolError { code: 1, object_id: 186, object_interface: "cosmic_corner_radius_layer_v1", message: "" }))': src/wayland/mod.rs:337
aoû 16 14:27:35 pop-os xdg-desktop-portal-cosmic[3771]: xdg_desktop_portal_cosmic::wayland: wayland thread crash; terminating
Troubleshooting Already Performed:
- Isolated ~/.config/cosmic to force default config regeneration (freeze persists).
- System is fully updated (apt full-upgrade).
- Verified this is not an AppArmor/namespaces issue (adjusting kernel sandbox parameters does not prevent the portal crash).
Environment:
- OS: Pop!_OS 24.04 LTS x86_64
- DE: COSMIC (Epoch)
cosmic_journal.txt
Description:
Following a recent update, launching native COSMIC applications (such as cosmic-files) results in spawned windows that are completely frozen and unresponsive to interaction.
Upon checking the system journal, it appears that xdg-desktop-portal-cosmic is encountering a fatal protocol error regarding cosmic_corner_radius_layer_v1 and completely terminating the Wayland thread. Because the portal crashes, the spawned application windows become orphaned UI zombies.
Steps to Reproduce:
Actual Behavior / Logs:
The terminal running the app displays missing theme keys warnings (e.g., list_button), but the actual fatal crash occurs in the background daemon.
From journalctl[cite: 1]:
Troubleshooting Already Performed:
Environment:
cosmic_journal.txt