I was experimenting with Cowork in my tenant just last week, so I was surprised when it suddenly stopped working. After digging a bit deeper, it turns out Microsoft has taken a clear stance: Anthropic AI models are currently restricted by default due to GDPR considerations, particularly around data processing outside the EU. Why Are Anthropic Models Disabled? For EU-based tenants, Microsoft has disabled Anthropic AI models by default to ensure compliance with GDPR and data sovereignty requirements.