Troubleshooting

ClamAV is missing or definitions are old

Install host ClamAV for every ClamUI package format, then update definitions:

clamscan --version
freshclam --version
sudo freshclam

Use the distribution commands in installation. In Flatpak, these commands must succeed on the host; ClamUI calls them with flatpak-spawn --host.

Daemon backend unavailable

The daemon backend needs clamd and clamdscan running. Check its service, then choose Auto or Clamscan if you do not need a persistent daemon:

sudo systemctl status clamav-daemon
sudo systemctl enable --now clamav-daemon
clamdscan --version

Fedora commonly uses clamd@scan and /etc/clamd.d/scan.conf:

sudo systemctl enable --now clamd@scan

Check LocalSocketMode and LocalSocketGroup when a running Fedora daemon is inaccessible. Backend reference lists socket paths and alternatives.

clamdscan receives targets through a newline-delimited file list. A pathname containing a newline cannot be represented there, so ClamUI rejects that daemon scan rather than scanning the wrong target. Use the Clamscan backend for that file after confirming the pathname.

Flatpak cannot scan a location or update ClamAV

Grant only the directory you need:

flatpak override --user --filesystem=/path/to/directory io.github.linx_systems.ClamUI

Database updates use host freshclam, which may need the host service’s usual permissions. ClamUI cannot modify host /etc/clamav without a valid version-matched privileged helper; it fails without changing host configuration.

File-manager action or tray icon is absent

For Flatpak context-menu actions, re-run Preferences → Behavior → Configure Integration, then restart the file manager or sign out/in. For a native Debian package, copy Nautilus scripts once:

mkdir -p ~/.local/share/nautilus/scripts
cp /usr/share/clamui/integrations/clamui-*.sh ~/.local/share/nautilus/scripts/
chmod +x ~/.local/share/nautilus/scripts/clamui-*.sh

Restart Nautilus after copying. Check that clamui is executable for native integrations.

The tray needs an SNI watcher. GNOME requires AppIndicator Support; native/source installations also need libdbusmenu bindings. The GUI remains usable when a tray is unavailable.

Scans are slow, fail, or find a false positive

• Use Auto or a running daemon for frequent scans; clamscan reloads the database each time.
• Confirm the account can read targets and do not unplug removable media during a scan.
• If clamscan reports unavailable or unreadable definition files, repair the host ClamAV setup or use a reachable daemon backend; ClamUI distinguishes missing definitions from definitions it cannot read.
• Keep ClamAV definitions current. For a suspected false positive, quarantine first, inspect provenance and hashes, and use multiple engines only if the file is safe to disclose. Do not upload sensitive files to third parties.
• Avoid unlimited archive limits: malicious archives can consume resources.

Quarantine, schedules, and logs

A restore refusal can mean the destination already exists or integrity verification failed; do not bypass the latter. Export important logs before using Clear All—clearing is permanent. Scheduled scans require either a user systemd timer or cron and a powered-on machine at run time. Test configuration without changing data:

clamui-scheduled-scan --dry-run
systemctl --user list-timers
crontab -l

Still stuck?

Collect the relevant Log entry, ClamAV version, package format, desktop environment, and exact error, then search or open a GitHub issue. Report vulnerabilities through the private security policy, not a public issue.