🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026
Affected versions: SUSE Linux Enterprise Server 16

📖 ~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

Opening a YaST module aborts with a Ruby exception in `/var/log/YaST2/y2log`.

Environment & Reproduction

Reproduces on hosts where a `yast2-*` package was partially updated.

Root Cause Analysis

Mismatched yast2-core and module versions cause API incompatibility.

Quick Triage

Check installed versions: `rpm -qa | grep yast2`.

Step-by-Step Diagnosis

Tail `/var/log/YaST2/y2log` while reproducing to capture the failing call.

Illustrative mockup for sles-16 — yast_module-crash_terminal
Terminal diagnostics for YaST module crashes on launch with Ruby trace — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Run `zypper install –force-resolution yast2 yast2-core` to align versions.

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Illustrative mockup for sles-16 — yast_module-crash_logs
Logs and evidence for YaST module crashes on launch with Ruby trace — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Launch the failing module via command line (`yast2 –ncurses `) to bypass GUI components.

Verification & Acceptance Criteria

`yast2 ` opens without exception and `y2log` shows no traceback.

Rollback Plan

Roll back the most recent zypper transaction via `zypper history` and `zypper rollback`.

Prevention & Hardening

Pin YaST package versions in `/etc/zypp/locks` during partial maintenance windows.

Linked to `D-Bus` errors when YaST tries to reach `org.opensuse.YaST`.

Related tutorial: View the step-by-step tutorial for sles-16.

View all sles-16 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

YaST troubleshooting guide for SLES 16.

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