Ubuntu 20.04 LTS – Common Problem 010 – Diagnosis and Fix

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Snap apps fail to start or crash immediately, impacting desktop productivity and packaged tool access.

Environment & Reproduction

Ubuntu 20.04 with snapd enabled and one or more snapped apps in disabled or broken state.

Root Cause Analysis

Corrupt snap revision, outdated base snap, missing interfaces, or snapd service malfunction.

Quick Triage

Run ‘snap list’, ‘snap changes’, and ‘systemctl status snapd’ to spot failed tasks.

Step-by-Step Diagnosis

Inspect failed change IDs, check confinement denials, and review ‘journalctl -u snapd’ logs.

Solution – Primary Fix

Refresh snaps with ‘sudo snap refresh’, reconnect required interfaces, and restart snapd service.

Solution – Alternative Approaches

Revert to previous revision, reinstall specific snap, or install apt package equivalent where available.

Verification & Acceptance Criteria

App launches normally, snap changes complete successfully, and no recurring snapd errors appear.

Rollback Plan

Use ‘snap revert ‘ or reinstall known-stable revision if latest refresh regresses.

Prevention & Hardening

Track critical snaps in canary hosts first and monitor snap refresh windows.

Related Errors & Cross-Refs

cannot mount squashfs, snap change in progress, and permission denials with strict confinement.

Related tutorial: View the step-by-step tutorial for Ubuntu 20.04 LTS.

View all Ubuntu 20.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

snapcraft documentation, Ubuntu snapd service docs, and confinement interface references.