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Akron has two separate state-restore workflows:
  • The StartPos tab’s Set and Load actions use Akron’s persistent StartPos snapshot for the selected StartPos slot.
  • The Capture StartPos State and Restore StartPos State bindings use the active 1-9 savestate slot. This path can use Speedrun Tool brokering and current-map compatibility overrides.

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StartPos capabilities

Setting a StartPos captures an in-memory native clone for same-process loads while a worker builds and validates the restart-safe v10 snapshot. After a restart, or when the in-memory copy is unavailable, Load reconstructs the state from that snapshot file. It contains room entities and components, their reference relationships, movement, timers, state machines, animation, coroutine progress, callbacks, registered helper state, Celeste’s random generator and nested random stack, visual runtime entities, gameplay render-buffer pixels, and audio state. Akron holds the Set or Load state through fixed-timestep catch-up updates until Celeste renders it. No external savestate or TAS mod is required. Room state still restores in full. Time and death statistics are the documented exception and do not rewind. Use the StartPos tab for player workflows: setting, loading, clearing, selecting a slot, mouse placement, and configuring respawn at StartPos behavior.

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Why persistent StartPos Set or Load may fail

Persistent StartPos Set or Load may fail if:
  • A Set capture is still finishing.
  • Celeste is paused, transitioning rooms, or running or skipping a cutscene.
  • The saved StartPos belongs to a different map SID or save-file slot.
  • The v10 snapshot file is missing, damaged, or incomplete.
  • The map, save file, mod set, runtime, or snapshot format differs from the capture environment.
  • The slot was set by an earlier Akron that built fresh rooms differently, so its restart copy uses a superseded snapshot format.
Attempt status does not block ordinary persistent StartPos actions. Invoking Set or Load records their Cheat classification even if a later runtime check fails.

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Recovery steps

1

Wait for a stable room

Resume Celeste, finish any room transition or cutscene, and wait for the previous Set capture to finish.
2

Use a non-submission setup

Use a non-submission setup for room-lab routing or tests that involve StartPos.
3

Verify the StartPos slot

Confirm that the active StartPos slot is set, belongs to the current map and save-file slot, and names the intended destination room. The room you load from can differ.
4

Check the snapshot

If the in-memory state is unavailable, confirm that the matching v10 snapshot still exists and was created with the current map, save file, mod set, runtime, and snapshot format.
5

Set the slot again after a snapshot format change

A slot the format move emptied leaves the slot list, so loading it reports that it was saved by an older Akron that built rooms differently. That slot predates a snapshot format change and cannot be recovered. Set the StartPos again. Akron does not convert older snapshots: an older snapshot describes a fresh room that this build no longer produces, so there is nothing correct to convert it into.
6

Document the issue

If the problem remains, record the map SID, save-file slot, Akron setup, StartPos slot, visible error, and logs. Attach screenshots when they show the failure.

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Snapshot format changes

A StartPos snapshot records where each room object sits in a clean reload of that room, so it only means anything against the fresh room the build that wrote it produced. When Akron changes what a clean reload contains, the snapshot format version changes with it, and snapshots written before the change are refused rather than read: an index that has shifted can pair two same-typed objects the wrong way round and report a successful load. The format also changes when a snapshot has to carry something it did not carry before, such as whether the map laid a saved entity out, because a snapshot without it cannot be checked against it. That map check covers the room a slot was set in; state a mod registers with Akron separately is checked by every other rule but not by the map. The current format is akron-reconstruction-v10. Slot positions, spawn settings, keybinds and every other setting survive a format change. The saved room state behind each slot does not, and has to be captured again with Set. .akr setup packs carry the same snapshots, so a pack made before the change has to be exported again as well.

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Capture and Restore StartPos State savestates

The similarly named Capture StartPos State and Restore StartPos State bindings do not use the persistent StartPos slot above. They save or load the active savestate slot from 1-9. This savestate path owns Speedrun Tool brokering and native-restore risk checks. Current Map Compatibility exposes Always Use Broker and Allow Unsafe StartPos Restore for this path. If capture or restore is blocked, check the active savestate slot, Speedrun Tool availability, and those current-map settings.
Unsafe native savestate overrides bypass risk blocking and are Cheat. Use them only for controlled testing in a non-submission setup. They do not repair a missing or damaged persistent StartPos snapshot.

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Safe Mode stat guards

Safe Mode stat guards prevent selected local stat fields from being altered by guarded Akron sessions. Suboptions that freeze deaths, jumps, or best-run stats are considered Cheat because they mutate or protect tracked statistics.