# Resource revision does not match

> Canonical HTML: https://screenrig.ai/problems/revision-conflict/

HTTP 412 · `revision_conflict`

## What it means

The API answers with HTTP 412 Precondition Failed and an `application/problem+json` document when the condition is Resource revision does not match. The document's `type` member is `https://screenrig.ai/problems/revision-conflict`, the address of this page, and its `code` member is `revision_conflict`.

## What to do

The resource changed since you read it. Read it again, reapply your change, and retry with its current revision (current_revision when present) as the expected revision (If-Match / --expect-rev).

## Player action

The Player action class is `hold_lkg`: Keep playing the last-known-good content and poll slowly.

## Reference

| Field | Value |
| --- | --- |
| Code | `revision_conflict` |
| HTTP status | `412 Precondition Failed` |
| Type | `https://screenrig.ai/problems/revision-conflict` |
| Player action | `hold_lkg` |

- [All problem types](https://screenrig.ai/problems/)
- [API reference](https://screenrig.ai/docs/api/#problems)
- [Problem registry YAML](https://screenrig.ai/docs/api/problems.yaml)