DOC: Screenshot capture failure with Flameshot on Ubuntu 24.04 LTS (GNOME/Wayland)

[JustinFntn]

Environment

• OS: Ubuntu 24.04.3 LTS (Noble Numbat)
• Desktop: GNOME Shell 46.0
• Display server: Wayland
• Installation method: sudo apt install flameshot
• Flameshot version: v12.1.0 (Debian 12.1.0-2build2)

Problem

On this setup, trying to take a screenshot with Flameshot results in the following error:

flameshot: error: Unable to capture screen

This happens when launching from the tray icon or desktop launcher.
After debugging, the issue appears to be related to screenshot permissions handled by xdg-desktop-portal on GNOME/Wayland.

Flameshot itself works correctly once the screenshot permissions are properly granted to the application.

Solution: Grant screenshot permissions via D-Bus

The following sequence fixes the problem permanently on Ubuntu 24.04 + GNOME 46 + Wayland.

⚠️ Run these commands as your regular user (no sudo), in a terminal inside your graphical session.

1. Reset existing screenshot permissions

dbus-send --session --print-reply=literal \
  --dest=org.freedesktop.impl.portal.PermissionStore \
  /org/freedesktop/impl/portal/PermissionStore \
  org.freedesktop.impl.portal.PermissionStore.DeletePermission \
  string:'screenshot' string:'screenshot' string:''

This clears any previous (possibly broken or denied) screenshot permission entries.

2. Explicitly grant screenshot permission to Flameshot

dbus-send --session --print-reply=literal \
  --dest=org.freedesktop.impl.portal.PermissionStore \
  /org/freedesktop/impl/portal/PermissionStore \
  org.freedesktop.impl.portal.PermissionStore.SetPermission \
  string:'screenshot' boolean:true string:'screenshot' \
  string:'org.flameshot.Flameshot' array:string:'yes'

• org.flameshot.Flameshot is the application ID from the desktop file.
• The array:string:'yes' value grants the screenshot permission.

3. Verify that the permission is stored

dbus-send --session --print-reply=literal \
  --dest=org.freedesktop.impl.portal.PermissionStore \
  /org/freedesktop/impl/portal/PermissionStore \
  org.freedesktop.impl.portal.PermissionStore.Lookup \
  string:'screenshot' string:'screenshot'

You should now see an entry containing org.flameshot.Flameshot and the granted permission.

4. Restart Flameshot

1. Quit Flameshot from the tray icon (top bar) – right click → Quit.
2. Start Flameshot again (from the app menu).
3. Try Take Screenshot from the tray icon

At this point, screenshots should work normally without the Unable to capture screen error.

[mmahmoudian]

Thanks, but this is somewhat already explained in our documentation:

https://flameshot.org/docs/guide/wayland-help/#unable-to-capture-screen-error

[mmahmoudian]

@borgmanJeremy
Do you think adding some more information in the error message is a good idea? For instance if we detect Wayland and got this error, print out the link to our documentation as well in the error

[borgmanJeremy]

@mmahmoudian Yes, i think thats a good idea. What link do you want to point to?