Users Report Severe Downgrade in Opus 5: Hallucinations and Math Errors
whatsallthiss · x · 2026-07-27
A user complained that Anthropic's Opus 5 feels like a remarkable downgrade compared to version 4.8. The user reported that Opus 5 blatantly lies about basic thermodynamics, messes up simple math, and constantly contradicts itself when asked to rethink core assumptions.
Related event: Opus 5 Faces User Backlash Over Self-Doubt and Capability Regression(5 posts)→
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