issue: Audio transcript broken at 0.6.42

[zilingzhang]

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• I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

v0.6.42

Ollama Version (if applicable)

No response

Operating System

ubuntu 24.04

Browser (if applicable)

Chrome 143

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:
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• 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

ASR works correctly.

Actual Behavior

Open webui throws a "Oops! It seems like the file format you're trying to upload is not supported. Please upload a file with a supported format and try again."

Steps to Reproduce

1. Run 0.6.42 ghcr.io/open-webui/open-webui:cuda
2. Start audio in chat
3. Received format error

Logs & Screenshots

2025-12-22 01:18:02.545 | ERROR | open_webui.utils.misc:strict_match_mime_type:637 - Failed to match mime type audio/wav: list
index out of range - {"trace_id": "c016792302aae3dcd1280b95bf3df0e1", "span_id": "ee98aa5b31424c78"}
Traceback (most recent call last):

  File "/usr/local/lib/python3.11/threading.py", line 1002, in _bootstrap
    self._bootstrap_inner()
    │    └ <function Thread._bootstrap_inner at 0xec9a751049a0>
    └ <WorkerThread(AnyIO worker thread, started 260122144141728)>
  File "/usr/local/lib/python3.11/threading.py", line 1045, in _bootstrap_inner
    self.run()
    │    └ <function WorkerThread.run at 0xec94a41dd940>
    └ <WorkerThread(AnyIO worker thread, started 260122144141728)>
  File "/usr/local/lib/python3.11/site-packages/anyio/_backends/_asyncio.py", line 986, in run
    result = context.run(func, *args)
             │       │   │      └ ()
             │       │   └ functools.partial(<function transcription at 0xec96cd177e20>, 
user=UserModel(id='48a50a0a-d095-48cf-b084-26a710fa0e21', email...
             │       └ <method 'run' of '_contextvars.Context' objects>
             └ <_contextvars.Context object at 0xec94a413bec0>

  File "/app/backend/open_webui/routers/audio.py", line 1159, in transcription
    if not strict_match_mime_type(stt_supported_content_types, file.content_type):
           │                      │                            │    └ <property object at 0xec9a70897650>
           │                      │                            └ UploadFile(filename='recording.wav', size=44732, 
headers=Headers({'content-disposition': 'form-data; name="file"; filename="r...
           │                      └ ['']
           └ <function strict_match_mime_type at 0xec98d86718a0>

> File "/app/backend/open_webui/utils/misc.py", line 625, in strict_match_mime_type
    match = mimeparse.best_match(supported, header)
            │         │          │          └ 'audio/wav'
            │         │          └ []
            │         └ <function best_match at 0xec98d86702c0>
            └ <module 'mimeparse' from '/usr/local/lib/python3.11/site-packages/mimeparse.py'>

  File "/usr/local/lib/python3.11/site-packages/mimeparse.py", line 215, in best_match
    return weighted_matches[-1][0][0] and weighted_matches[-1][2] or ''
           │                              └ []
           └ []

IndexError: list index out of range

Additional Information

No response

[owui-terminator]

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[spammenotinoz]

Same, bug introduced in 0.6.42
2025-12-22 12:50:39.727 | ERROR | open_webui.utils.misc:strict_match_mime_type:637 - Failed to match mime type audio/wav: list index out of range

There is a workaround,
In Admin Settings, set Supported MIME Types = audio/wav
Appears the defaults have been lost.

[spammenotinoz]

Unsure what the defaults were but these also fix the issue, while covering more audio types.

audio/*

or

audio/mpeg, audio/wav, audio/ogg, audio/x-m4a

[i-iooi-i]

Had the same problem

[firestrife23]

Following, having same issues as above.

[ALIENvsROBOT]

@tjbck could you please fix it. The latest version has the same issue !