Anthropic disabled Fable 5 and Mythos 5 on June 12 after a US government export-control order
The order bars foreign nationals, so every customer lost access while compliance is sorted out
The trigger was a narrow jailbreak that asked the model to fix flaws in a codebase
Opus 4.8 and every other Claude model still work, so that is where I moved my pipelines
Six days after I started routing real work to Claude Fable 5, it vanished. On June 12 Anthropic disabled both Fable 5 and Mythos 5 worldwide, and the reason is not a billing glitch or a quiet deprecation. A US government directive forced the shutdown. Here is what actually happened, why it happened, and the calm fallback I used so none of my projects stalled.
