Copilot Studio Agent Cannot Use Uploaded Files as Knowledge: Fix

You uploaded documents to your Copilot Studio agent, but the agent ignores them during conversations. This usually happens because the files are not linked to a knowledge source with the correct configuration. The agent can only read content from knowledge sources that are enabled and properly indexed. This article explains why uploaded files fail to appear as knowledge and how to fix the issue in Copilot Studio.

Why Copilot Studio Ignores Uploaded Files

Copilot Studio stores uploaded files in a knowledge source called Uploaded files. However, the agent only uses this source if two conditions are met. First, the knowledge source must be toggled on in the agent’s Topics settings. Second, each file must be under 10 MB and in a supported format. If either condition fails, the agent silently skips the source without any error message.

The most common root cause is that the knowledge source is disabled. By default, new agents do not have the Uploaded files source turned on. Another frequent cause is file corruption or an unsupported extension like .png or .json. The agent does not warn you when a file fails to index.

How Knowledge Sources Work in Copilot Studio

Copilot Studio agents use knowledge sources to answer questions. You can connect external sources like SharePoint, Dataverse, or public websites. The Uploaded files source is a built-in option that lets you add files directly. When you upload a file, Copilot Studio indexes its text content. The agent then searches this index during conversations. If the source is disabled or the file is corrupted, the agent has no data to search.

Steps to Enable Uploaded Files as Knowledge

Follow these steps to check and enable the Uploaded files source for your Copilot Studio agent.

1. Open your agent in Copilot Studio
   Sign in to Copilot Studio at copilotstudio.microsoft.com. Select the agent that is ignoring the uploaded files. The agent opens in the configuration editor.
2. Go to the Topics tab
   In the left navigation pane, click Topics. This area controls what the agent can discuss and which knowledge sources it can use.
3. Open the Knowledge section
   At the top of the Topics page, click the Knowledge tab. You see a list of all connected knowledge sources. Look for a source named Uploaded files.
4. Toggle the Uploaded files source on
   If the toggle next to Uploaded files is gray, click it to turn it blue. This enables the source. If you do not see the Uploaded files source at all, click Add knowledge and select Uploaded files.
5. Verify your uploaded files
   Still on the Knowledge tab, click the Uploaded files source name. A panel opens showing all uploaded documents. Check that each file meets these requirements:
   • File size is under 10 MB
   • File extension is .pdf, .docx, .pptx, .xlsx, or .txt
   • File is not password protected or encrypted

   If any file fails these checks, remove it and re-upload a corrected version.

6. Save and test the agent
   Click Save at the top of the page. Then open the test chat pane on the right side of the editor. Ask a question that your uploaded file can answer. For example, if you uploaded a product catalog, ask “What is the price of item X?” The agent should now return information from the file.

If Copilot Studio Still Ignores Uploaded Files

If the agent still does not use the files after enabling the source, check these specific scenarios.

Uploaded Files Source Does Not Appear in the Knowledge List

The Uploaded files source is only available after you upload at least one file. Go to the Knowledge tab and click Add knowledge. Select Uploaded files. A file picker opens. Upload your documents. After the upload completes, the source appears in the list. Then toggle it on.

Agent Returns Generic Responses Instead of File Content

This usually means the file was not indexed correctly. Remove the file from the Uploaded files source and upload it again. Make sure the file contains readable text. Scanned PDFs without OCR are not indexed. Convert scanned PDFs to searchable PDFs using a PDF tool before uploading.

Uploaded Files Exceed the Storage Limit

Copilot Studio limits each Uploaded files source to 20 files and a total of 50 MB. If you exceed either limit, the source stops working. Check the file count and total size by clicking the Uploaded files source name in the Knowledge tab. Remove older or unnecessary files to stay under the limit.

Agent Uses a Different Knowledge Source First

Copilot Studio agents can have multiple knowledge sources. The agent may return answers from a SharePoint source or a public website before checking your uploaded files. To prioritize uploaded files, remove other knowledge sources temporarily. On the Knowledge tab, toggle off sources like SharePoint or Dataverse. Test the agent again. If it now uses the uploaded files, re-enable the other sources one at a time to confirm which source was overriding.

Uploaded Files vs Other Knowledge Sources: Key Differences

Item	Uploaded Files	SharePoint or Dataverse
File types supported	.pdf, .docx, .pptx, .xlsx, .txt	All file types supported by SharePoint
File size limit	10 MB per file, 50 MB total	Depends on SharePoint tenant limits
Number of files	Maximum 20 files per source	No fixed limit, depends on site storage
Update method	Manual upload or replace	Syncs automatically from SharePoint
Indexing delay	Usually under 5 minutes	Can take up to 24 hours

If you need to use more than 20 files or files larger than 10 MB, connect a SharePoint document library as the knowledge source instead. Upload your files to SharePoint and then add that library to your Copilot Studio agent.