# SnapshotIntegrityError

Loading (or forking) a compacted run found a snapshot problem: the blob referenced by the run's `runtime.snapshot` event is missing from the sidecar table, or does not hash to the state hash the event pinned. The runtime refuses to project it — a corrupted snapshot silently producing wrong state would defeat the entire honesty model (CONTRACT v1.5 #2).

## Quick fix

The archived prefix is the ground truth the snapshot summarizes. Audit it:

```python
from activegraph.store.retention import verify_snapshot
verify_snapshot("runs.db", run_id)
```

- If it **raises too**: the archive itself no longer reproduces the pinned hash — restore the store file from backup.
- If it **passes**: the archive is intact and only the sidecar row is damaged; re-run `compact` semantics by rebuilding the blob from the archive (or restore the file from backup — simpler and equally correct).

## What's related

- [`retention-pinned-error`](https://docs.activegraph.ai/reference/errors/retention-pinned-error/index.md)
- [Replay](https://docs.activegraph.ai/concepts/replay/index.md) — the projection-from-log model the snapshot short-circuits.