Anthropic Claude Faces Login Outage Alongside Microsoft Issues
Anthropic's Claude AI services suffered login failures and degraded performance on Friday, November 13, disrupting access to claude.ai, Claude Code, Claude Console, and Claude Cowork, LiveMint reported. According to LiveMint, Anthropic logged the authentication incident on its status dashboard at 9:58 UTC (3:28 p.m. IST), while Downdetector recorded 2,895 user reports around 3:45 p.m. compared with a baseline of two. Jagran Josh reported that Anthropic deployed a fix at 4:35 p.m. IST and marked the authentication incident resolved at 5:28 p.m. IST, though a later status update flagged elevated errors affecting claude.ai, the Claude API, and Claude Code.
Separate Microsoft 365 Connector Disruption
LiveMint reported that Anthropic has also been dealing with a separate, ongoing issue since Thursday involving its Microsoft 365 connector, which links Claude to Outlook, SharePoint, Teams, and calendars. Anthropic attributed that connector failure to the global Microsoft 365 outage, which began around 18:00 UTC on Thursday when overloaded Microsoft servers failed health checks across 74 countries, Nacionale reported. OpenAI similarly reported on Thursday at 1:29 p.m. that its Microsoft 365 connector for ChatGPT was experiencing degraded performance and elevated errors, according to LiveMint. On October 25, 2026, every current Claude model failed simultaneously in the worst of five model incidents in 33 hours, among 49 incidents logged since August 12, 2026, according to Deployflow. Mail, calendar, and search tools in the Microsoft 365 connector remained failing for most requests, according to Anthropic.
Recent Anthropic Incident History
Jagran Josh noted that Anthropic drew no link between Friday's Claude authentication errors and the Microsoft 365 outage. According to Nacionale, citing monitoring data from Pulsetic, Anthropic recorded 46 separate incidents across the preceding 90 days, averaging 41 minutes to recover. Nacionale added that earlier November disruptions included a 26-minute outage on November 8 affecting Claude Fable 5.1 and four-minute errors on November 10 affecting Fable 5.2 and Mythos 5.2. During the November 13, 2026 disruption, Anthropic's Claude Platform on AWS, Claude in Microsoft Foundry, and Claude Models on Google Cloud remained operational, according to Anthropic.