[GH-ISSUE #18187] issue: [BUG] Retrieval Error IndexError

GiteaMirror commented

2026-04-20 00:45:27 -05:00

Owner

Originally created by @Schwenn2002 on GitHub (Oct 9, 2025).
Original GitHub issue: https://github.com/open-webui/open-webui/issues/18187

Check Existing Issues

I have searched for any existing and/or related issues.
I have searched for any existing and/or related discussions.
I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

v0.6.33

Ollama Version (if applicable)

v0.12.3

Operating System

Ubuntu 24.04

Browser (if applicable)

API or Chrom Or Edge

Confirmation

I have read and followed all instructions in README.md.
I am using the latest version of both Open WebUI and Ollama.
I have included the browser console logs.
I have included the Docker container logs.
I have provided every relevant configuration, setting, and environment variable used in my setup.
I have clearly listed every relevant configuration, custom setting, environment variable, and command-line option that influences my setup (such as Docker Compose overrides, .env values, browser settings, authentication configurations, etc).
I have documented step-by-step reproduction instructions that are precise, sequential, and leave nothing to interpretation. My steps:
Start with the initial platform/version/OS and dependencies used,
Specify exact install/launch/configure commands,
List URLs visited, user input (incl. example values/emails/passwords if needed),
Describe all options and toggles enabled or changed,
Include any files or environmental changes,
Identify the expected and actual result at each stage,
Ensure any reasonably skilled user can follow and hit the same issue.

Expected Behavior

If I create a collection, questions in the chat should be able to be executed against this collection and valid answers should be made based on the documents.

Actual Behavior

When I create a new collection with files, they are created correctly. When I request a single file from the collection in the chat, I get the correct response. However, as soon as I request the entire collection with hybrid search, I get an IndexError, docker-log:

Calling the API results in a payload error (http code 400).

However, I can query a collection created with an older version.

Steps to Reproduce

Create Collection with some Files (open webui v0.6.33)
Chat with single documents is working
Chat with whole collection with hybrid search --> IndexError in merge_and_sort_query_results (docker.log), API payload error (http 400)

Logs & Screenshots

File "/app/backend/open_webui/routers/retrieval.py", line 2253, in query_collection_handler
return query_collection_with_hybrid_search(
└ <function query_collection_with_hybrid_search at 0x756c08a8ef20>

File "/app/backend/open_webui/retrieval/utils.py", line 448, in query_collection_with_hybrid_search
return merge_and_sort_query_results(results, k=k)
│ │ └ 60
│ └ [{'documents': [], 'metadatas': [], 'distances': []}]
└ <function merge_and_sort_query_results at 0x756c08a8e700>

File "/app/backend/open_webui/retrieval/utils.py", line 271, in merge_and_sort_query_results
distances = data["distances"][0]
└ {'documents': [], 'metadatas': [], 'distances': []}

IndexError: list index out of range

Additional Information

No response

Originally created by @Schwenn2002 on GitHub (Oct 9, 2025). Original GitHub issue: https://github.com/open-webui/open-webui/issues/18187 ### Check Existing Issues - [x] I have searched for any existing and/or related issues. - [x] I have searched for any existing and/or related discussions. - [x] I am using the latest version of Open WebUI. ### Installation Method Docker ### Open WebUI Version v0.6.33 ### Ollama Version (if applicable) v0.12.3 ### Operating System Ubuntu 24.04 ### Browser (if applicable) API or Chrom Or Edge ### Confirmation - [x] I have read and followed all instructions in `README.md`. - [x] I am using the latest version of **both** Open WebUI and Ollama. - [x] I have included the browser console logs. - [x] I have included the Docker container logs. - [x] I have **provided every relevant configuration, setting, and environment variable used in my setup.** - [x] I have clearly **listed every relevant configuration, custom setting, environment variable, and command-line option that influences my setup** (such as Docker Compose overrides, .env values, browser settings, authentication configurations, etc). - [x] I have documented **step-by-step reproduction instructions that are precise, sequential, and leave nothing to interpretation**. My steps: - Start with the initial platform/version/OS and dependencies used, - Specify exact install/launch/configure commands, - List URLs visited, user input (incl. example values/emails/passwords if needed), - Describe all options and toggles enabled or changed, - Include any files or environmental changes, - Identify the expected and actual result at each stage, - Ensure any reasonably skilled user can follow and hit the same issue. ### Expected Behavior If I create a collection, questions in the chat should be able to be executed against this collection and valid answers should be made based on the documents. ### Actual Behavior When I create a new collection with files, they are created correctly. When I request a single file from the collection in the chat, I get the correct response. However, as soon as I request the entire collection with hybrid search, I get an IndexError, docker-log: Calling the API results in a payload error (http code 400). However, I can query a collection created with an older version. ### Steps to Reproduce 1. Create Collection with some Files (open webui v0.6.33) 2. Chat with single documents is working 3. Chat with whole collection with hybrid search --> IndexError in merge_and_sort_query_results (docker.log), API payload error (http 400) ### Logs & Screenshots > File "/app/backend/open_webui/routers/retrieval.py", line 2253, in query_collection_handler return query_collection_with_hybrid_search( └ <function query_collection_with_hybrid_search at 0x756c08a8ef20> File "/app/backend/open_webui/retrieval/utils.py", line 448, in query_collection_with_hybrid_search return merge_and_sort_query_results(results, k=k) │ │ └ 60 │ └ [{'documents': [], 'metadatas': [], 'distances': []}] └ <function merge_and_sort_query_results at 0x756c08a8e700> File "/app/backend/open_webui/retrieval/utils.py", line 271, in merge_and_sort_query_results distances = data["distances"][0] └ {'documents': [], 'metadatas': [], 'distances': []} IndexError: list index out of range ### Additional Information _No response_

GiteaMirror added the bug label 2026-04-20 00:45:27 -05:00

GiteaMirror closed this issue

2026-04-20 00:45:27 -05:00

GiteaMirror commented

2026-04-20 00:45:28 -05:00

Author

Owner

@rgaricano commented on GitHub (Oct 9, 2025):

It's addressed in dev

@rgaricano commented on GitHub (Oct 9, 2025): It's addressed in dev

GiteaMirror commented

2026-04-20 00:45:29 -05:00

Author

Owner

@tjbck commented on GitHub (Oct 9, 2025):

4e763e8aa8

@tjbck commented on GitHub (Oct 9, 2025): 4e763e8aa89a8532626351a6c2f904c4f133f49e

[GH-ISSUE #18187] issue: [BUG] Retrieval Error IndexError #18527

Check Existing Issues

Installation Method

Open WebUI Version

Ollama Version (if applicable)

Operating System

Browser (if applicable)

Confirmation

Expected Behavior

Actual Behavior

Steps to Reproduce

Logs & Screenshots

Additional Information