Post‑Mortem: Android 5.61.0 Patient‑Info Crash

Incident Window	20 May 2025 (17:00 CEST release) – 26 May 2025 (14:00 CEST hot‑fix)
Severity	Critical (patients blocked from sending actions containing Patient Information)
Platforms Affected	Android only (v5.61.0). iOS unaffected.

1 Executive Summary

Android version 5.61.0 introduced a problem causing an immediate app crash whenever a patient submitted an action that included patient information fields. The defect was first reported to support on 22 May and confirmed as a widespread production issue on 26 May. A hot‑fix (v5.61.1) was released within four hours of confirmation. No alerts were missed and no clinical risk materialised, but 167 patients (0.26 % of the active Android user base) experienced this issue up to six days.

2 Impact

Metric	Value
Unique patients affected	167 (0.26 % of active Android patients)
Duration of impact	6 days (20–26 May 2025)
Organisations affected	All (global rollout)
Clinical alerts missed	0
SLA breach	None – MTTR 4 h, inside 24 h SLA

Clinical Severity: No direct patient harm. Crashes occurred before data left the device, therefore no medical alerts were generated or lost.

SLA Clarity: We calculate from the moment that we have confirmed the Production Issue.

3 Timeline

Date & Time (UTC)	Event
20 May 17:00	v5.61.0 released to production (rollout starts at 0% and within 7-8 days reaches 100%)
22 May 09:12	First support ticket received (insufficient detail)
22–25 May	Isolated crash reports
26 May 09:30	Second support ticket with reproduction steps
26 May 10:00	2nd Line Support and Testers reproduces issue
26 May 10:30	Root cause identified; workaround not feasible.
26 May 10:41	InStatus Incident published.
26 May 11:16	Fix is created, tested for Quality Assurance
26 May 14:42	Hotfix is approved by Google and released directly for all users on version 5.61.0.

4 Root Cause Analysis

Update of Android SDK made it required to make some types explicit which was previously not required.

5 Mitigation & Resolution

Code fix – Changed list generic from Any to Serializable.
Hot‑fix release – v5.61.1, fully rolled out in < 4 hours after Production Issue confirmed.

6 Communication

External
- Status Page incident opened 26 May 08:00, updated hourly until resolved.
- Support responded to all related tickets with ETA and resolution confirmation.
Internal
- Summary posted in #luscii-general after resolution.

7 Lessons Learnt & Preventive Actions

Area	Action
Testing	Expand regression suite with ↳ patient‑info submission on Android & iOS.
Architecture	Accelerate migration to Jetpack Compose to eliminate legacy Parcelable patterns (part of Major Maintenance roadmap)
Monitoring	Lower crash‑rate threshold for Slack alerts
Process	Review crash reports within 1 week of release as default checklist item

Post‑Mortem: Android 5.61.0 Patient‑Info Crash