Elevated errors: Invalid `signature` in `thinking` block
Jan 23, 05:09 UTCJan 23, 07:47 UTC
Duration
2h 38m
Impact
Minor
Root cause
Not disclosed
Anthropic, 90 days
94 incidents
Affected
Not listed by the vendor.
Final update
This issue is resolved for new requests. However, for responses from one platform received between 2026-01-23 00:00 UTC - 2026-01-23 08:00 UTC that are subsequently included in requests sent to a different platform, there may still be errors.
Timeline
- Resolved · Jan 23, 07:47 UTC
This issue is resolved for new requests. However, for responses from one platform received between 2026-01-23 00:00 UTC - 2026-01-23 08:00 UTC that are subsequently included in requests sent to a different platform, there may still be errors.
More from Anthropic
Full history| Started | Incident | Impact | Duration |
|---|---|---|---|
| Sep 2200:57 UTC | Elevated errors for multiple models | major | 1h 38m |
| Sep 1616:18 UTC | Issues with Google Play subscriptions | none | 33m |
| Sep 1509:48 UTC | Intermittent error spikes for Claude Mythos 5.1 and Claude Fable 5.1 | major | 1h 26m |
| Sep 1114:19 UTC | Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1 | major | 17m |
| Sep 1021:43 UTC | Elevated latency on the Claude API for some users | minor | 1h 41m |
| Sep 1015:54 UTC | Degraded functionality for Claude Cowork on Windows | major | 4d 3h |
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.