Power Platform Community Forum Thread Details

Hi all,

I’m struggling to get a Copilot Studio agent to reference knowledge files reliably.

I can create the agent without issues, and when I upload only 1–2 files it works as expected. However, once I uploaded ~450 files, the agent stopped returning any responses or references at all. Even when I explicitly instruct it to open or reference a specific file, it responds that the file cannot be found.

All files are uploaded as local files and are contained within a single File Group.

Has anyone experienced similar behaviour or hit a limit with larger file groups?

Thanks in advance.

Categories:

General topics

Hello,

Copilot Studio knowledge file groups do not scale linearly.

When you upload hundreds of files into a single File Group, the agent’s retrieval layer silently degrades and may stop grounding entirely — even though the files appear “uploaded successfully”.

In Microsoft Copilot Studio, the “Upload files as knowledge” feature relies on a managed RAG system built on Microsoft Dataverse search and vector embeddings. When a small number of documents are uploaded, the system retrieves relevant chunks reliably and grounds responses.
However, as hundreds of files are added, the number of indexed chunks grows dramatically, making it harder for the retrieval system to find high-confidence matches. This leads to responses that appear as if files cannot be found, even though they are indexed. The issue is not a storage or file limit but a retrieval scalability limitation.
The recommended approach is to split documents into smaller, focused file groups or use Azure AI Search for large document collections.