| Missing initiative and map path | Ask for the smallest missing input. |
| Existing map directory for a new initiative | Offer resume, an explicit new slug, or abort; never overwrite. |
.context is not ignored | Stop and ask for a safe ignored location or permission to update ignore rules. |
| External tracker requested | Stop with UNSUPPORTED BACKEND; do not call its API or MCP tools. |
| No frontier but fog remains | Report the blocked area and ask for the human decision or access needed to sharpen the next ticket. |
| Conflicting or stale map metadata | Reconcile from ticket files and report the correction before work. |
| No map owner in a parallel run | Stop and ask the user to identify one owner before any claim or worker write. |
| Competing claim | Yield the ticket and choose another frontier item or stop. |
| Requested ticket unavailable | Stop and report whether the named ticket is blocked, claimed, resolved, out of scope, or missing; do not resolve a different ticket. |
| Malformed canonical map or ticket | Stop. Do not infer or repeat work; recover only from a validated temporary file, handoff, or owner-confirmed source. |
| Interrupted write | Keep the previous canonical file, validate or discard only this session's temporary file, then resume from canonical ticket state and rebuild derived map data. |