What it checks
Meta’s two-step flow (create container → publish) holds the container for 24 hours. If our polling sees the container inEXPIRED state at publish time, this rule fires.
In practice this only matters for long-deferred publishes — synchronous POST /v1/posts runs end-to-end in seconds.
Remediation
Retry the publish with the sameIdempotency-Key. The dispatcher creates a fresh container on each attempt.
Related
threads.container.expired— Threads-specific shape.threads.container.error— non-expiry container failures.