This error means Alembic (Phoenix's migration tool) cannot find the migration revision 'a20694b15f82'. This typically happens if you previously ran a newer version of Phoenix (which created that migration), then downgraded to an older version that doesn't include it. To resolve, ensure you are running the latest Phoenix version so all expected migrations are present. If you must downgrade, you need to manually apply down migrations using Alembic and the Phoenix repo, but this can be risky and may require database intervention鈥攕ee <https://github.com/Arize-ai/phoenix/blob/main/docs/section-self-hosting/upgrade/migrations.md|migration docs> and <https://arize-ai.slack.com/archives/C04R3GXC8HK/p1726072834.159089|Slack discussion>.
Would you like more detail on how to manually resolve or reset the migration state?
Sources:
- <https://arize-ai.slack.com/archives/C04R3GXC8HK/p1726072834.159089|Slack thread: Alembic ResolutionError>
- <https://github.com/Arize-ai/phoenix/blob/main/docs/section-self-hosting/upgrade/migrations.md|migration docs>
