## Problem

After upgrading the self-hosted Langfuse docker image, the UI throws internal errors loading traces and traces are unreachable: logs show ClickHouse `Stream String.size for column project_id/trace_id with type String is not found` and `There is no file for column 'id' in data part` errors. CHECK TABLE found 17 of 100 parts failing on the observations table.

## Verified fix

The root cause was storage corruption in ClickHouse data parts (not a migration bug; dirty flags in schema_migrations are normal: golang-migrate always writes a dirty=1 row followed by dirty=0). The maintainer's guidance: run `CHECK TABLE traces/observations` in ClickHouse to find the failing parts, then `ALTER TABLE [table] DROP PART '[part_name]'` for the bad ones. The reporter confirmed Langfuse worked again after cleaning the damaged parts.

Source: https://github.com/langfuse/langfuse/issues/12172