field data type: 104 is not supported

[Somebi]

First of all, error is shown as [Object object] i had to fork/refactor/compile/re-pack and try from local file, then i could read that error message:

● claude-context - get_indexing_status (MCP)(path: "/var/local/agentic")
  ⎿ ❌ Codebase '/var/local/agentic' indexing failed.                                                                                                                                    
    🚨 Error: { extra_info: {}, error_code: 'IllegalArgument', reason: 'invalid parameter[expected=valid field][actual=field data type: 104 is not supported]', code: 1100, retriable:
    false, detail: 'invalid parameter[expected=valid field][actual=field data type: 104 is not supported]' }
    📊 Failed at: 0.0% progress
    🕐 Failed at: 1/19/2026, 5:04:47 PM
    💡 You can retry indexing by running the index_codebase command again.

and after some research in codex and it found that issue:
Why the error happens + fix

The error you saw (field data type: 104 is not supported) indicates your Milvus instance doesn’t support SparseFloatVector, which is required for hybrid/BM25 collections. Claude Context defaults to hybrid mode, so collection creation fails at 0%.

The fix now automatically falls back to non-hybrid collections when this error is detected, so indexing should proceed without manual config changes. If you want to force this behavior immediately, you can also set HYBRID_MODE=false in the MCP env to skip hybrid creation entirely (optional).

After setting HYBRID_MODE=false, error disappeared and it is now working, but the bug is still there.

I'm using local milvusdb/milvus:v2.3.21 in docker container.

[Somebi]

Somebi@886a459

Here is the fix for this.