Dify 1.17.1 needs a staged Weaviate upgrade or search breaks

Dify's 1.17.1 release note opens with a warning instead of a feature list. Self-hosted deployments running the bundled Weaviate vector store move from version 1.27.0 to 1.39.2, twelve minor versions in one jump, and Weaviate doesn't support skipping minors during an upgrade. Pull the new image, restart, and vector search can break silently. Not an error, not a failed health check. It just stops returning correct results, and the notes say the damage is permanent, per Dify's release notes on GitHub.

The people this doesn't touch: fresh installs, anyone on external Weaviate, anyone on a different vector store entirely. The people it does touch are exactly the ones most likely to miss it. A standard self-hosted Dify deployment updates with docker compose pull and a restart. That workflow has no step where anyone reads twelve versions of Weaviate changelog before running it.

This is what happens when a vector database becomes an invisible dependency. Teams pick Dify for the workflow builder and the knowledge base UI, not for opinions about which embedded database ships underneath. Weaviate's own multi-version upgrade path exists because skipping steps corrupts data, and Dify inherited that constraint the moment it bundled the database instead of treating it as pluggable infrastructure.

The release note doesn't say how to detect a broken index after the fact, or whether a broken deployment can be repaired without rebuilding the knowledge base from source documents. Running self-hosted Dify with the bundled vector store means reading the staged upgrade path before pulling, not after search results go quiet.