issue: Upload to knowledge base sometimes fails with error 400 The content provided is empty

[YetheSamartaka]

Check Existing Issues

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• I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

0.6.13

Ollama Version (if applicable)

0.6.8

Operating System

Ubuntu 22.04

Browser (if applicable)

No response

Confirmation

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Expected Behavior

File is uploaded without issues

Actual Behavior

File is sometimes uploaded with errors

Steps to Reproduce

When I use the official cookbok and the code to upload a file:
https://github.com/open-webui/cookbook/blob/main/knowledge/add-to-knowledge.ipynb

def upload_file(file_path):
url = f'{WEBUI_URL}/api/v1/files/'
headers = {
'Authorization': f'Bearer {TOKEN}',
'Accept': 'application/json'
}
files = {'file': open(file_path, 'rb')}
response = requests.post(url, headers=headers, files=files)
return response.json()

It can return the file_id before the file is actually processed. So when I use another method to add it to the knowledge, it fails:

def add_file_to_knowledge(knowledge_id, file_id):
url = f'{WEBUI_URL}/api/v1/knowledge/{knowledge_id}/file/add'
headers = {
'Authorization': f'Bearer {TOKEN}',
'Content-Type': 'application/json'
}
data = {'file_id': file_id}
response = requests.post(url, headers=headers, json=data)
return response.json()

I get the following error:
Error 400: The content provided is empty. Please ensure that there is text or data present before proceeding

Logs & Screenshots

I am using bge-m3 embedding model and apache tika

Additional Information

No response

[YetheSamartaka]

I have found out that people are having similar issues:
#13600

[lrnmid]

我发现人们也有类似的问题：#13600

我也有这种问题，但是我解决了，请查看你的ocr设置，看看你是用的哪种。建议用默认的，我怀疑是因为文件过大或者，ocr处理能力的问题

[YetheSamartaka]

I have OCR turned off. I only upload .md files.

[tjbck]

Could you share the file you uploaded? @jackthgu

[msonstei]

I ran into the same issue today. I wrote a function to check the status of the file until status = 'completed', then I let the knowledge upload happen.

[thiswillbeyourgithub]

I finally figured out the issue. It's actually a race condition: when you do a request to upload a file, the request returns as soon as the file was sent. But openwebui then starts extracting the content (via tika for example) then computing embeddings. It seems that as long as both (or at least the extraction) are not done the file will have a ["data"]["content"] value set to "". So if you try to assign that new file to the knowledge base it will fail because it thinks the file is empty. The solution on the client side is to add a loop that waits for the file to be fully processed before adding it to the knowledge base.

On the server side the fix should be to not crash if we assign a pending file to a knowledge base, or to refuse to add it but mention that it's because it's still pending.