Claude Fable 5 experiencing degraded performance
Jul 16, 21:05 UTCJul 16, 22:04 UTC
Duration
59m
Impact
Minor
Root cause
Not disclosed
GitHub, 90 days
69 incidents
Affected
Not listed by the vendor.
Final update
On July 16, 2026, GitHub Copilot users experienced elevated errors when using Claude Fable 5 from 17:33 UTC until mitigation at 22:04 UTC. The average error rate was 1.4%, with a maximum error rate of 30.85%. The issue was caused by degradation at an upstream model provider; other Copilot models were not significantly affected, and users could avoid the impact by selecting another model or Auto. Service recovered after the provider mitigated the degradation.
Timeline
- Resolved · Jul 16, 22:04 UTC
On July 16, 2026, GitHub Copilot users experienced elevated errors when using Claude Fable 5 from 17:33 UTC until mitigation at 22:04 UTC. The average error rate was 1.4%, with a maximum error rate of 30.85%. The issue was caused by degradation at an upstream model provider; other Copilot models were not significantly affected, and users could avoid the impact by selecting another model or Auto. Service recovered after the provider mitigated the degradation.
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Sources: vendors' own status pages, published postmortems and SEC 8-K Item 1.05 filings, read daily. Times as reported. Logos via logo.dev; trademarks belong to their owners.