## TL;DR

For "chromadb.errors.InternalError: Error executing plan: Error sending backfill request to compactor": using a v1.0.x client/server against a database created by v0.6.3 fails with chromadb.errors.InternalError because the 0.6.3-to-1.0.x migration (00005-max-seq-id-int.sqlite.sql) failed to apply cleanly.

```text
chromadb.errors.InternalError: Error executing plan: Error sending backfill request to compactor
```

## Steps

1. Using a v1.0.x client/server against a database created by v0.6.3 fails with chromadb.errors.InternalError because the 0.6.3-to-1.0.x migration (00005-max-seq-id-int.sqlite.sql) failed to apply cleanly. Maintainer-verified fix: delete the failed migration record, then re-run your query: sqlite3 [persist_dir]/chroma.sqlite3 "delete from migrations where dir='metadb' and filename='00005-max-seq-id-int.sqlite.sql';". Also, if you have a large base of existing 0.6.3 users, pin the 0.6.3 version for now rather than upgrading across the 1.0 boundary until the upgrade path is hardened.

## When to use

You are seeing this: Issue chroma-core/chroma#4217 (closed, 27 comments): ### What happened? Use this skill when you run into "Using v1.0.3 client/server with a database created by v0.6.3 client/server causes `chromadb.errors.InternalError`".

## When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

## Versions

Versions mentioned in the source: using v1.0.3, by v0.6.3, v1.0, 0.6.3-to, existing 0.6.3. If you are on something much newer or older, the details may have shifted.

## Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

## Edge cases

- Also, if you have a large base of existing 0.6.3 users, pin the 0.6.3 version for now rather than upgrading across the 1.0 boundary until the upgrade path is hardened.

## Sources

- https://github.com/chroma-core/chroma/issues/4217