Copilot 365 Chat cannot publish generated Word (.docx) outputs as downloadable attachments (blocking work)

Question

Impact: Copilot Chat can read uploaded Word files, but when it generates a new Word document (e.g., appendix tables), the chat UI does not surface any downloadable attachment or URL. This prevents completion of document‑production workflows and blocks my work.

Environment:

• Product: Microsoft Copilot Chat (chat surface)
• Account context: [Work tenant / Personal account] (fill in)
• Browser/app: [Edge/Chrome/Teams/Outlook/etc.] (fill in)
• Date/time: 28 Apr 2026, ~12:00–13:00 ET
• Location/timezone: ET

Reproduction steps:

1. Upload a Word document (.docx) into Copilot Chat.
2. Ask Copilot to generate a new Word document (e.g., “produce and publish Appendix A tables as a Word file”).
3. Copilot attempts to create the .docx, but no attachment appears (no link, no downloadable file).
4. In some attempts, the system returns the error: “Object reference not set to an instance of an object.”

Expected result: A generated .docx should appear as a downloadable attachment (or a stable file link) in the chat.

Actual result: No attachment appears; no download link is shown. File cannot be retrieved.

Error text observed:

• “Object reference not set to an instance of an object.”

Business justification: This blocks creating submission‑ready Word documents (appendices/tables) and prevents completing document merges and publishing updated versions.

Answer 1

The described behavior (Copilot Chat not returning a downloadable .docx when asked to “produce and publish” a new Word file, and intermittently showing “Object reference not set to an instance of an object”) is not documented as a supported end‑to‑end scenario in the provided material.

From the context, Copilot Chat and Copilot in Edge can:

• Analyze and summarize uploaded files, including Word documents, PDFs, PowerPoint, and Excel.
• Treat uploaded file content as if it were pasted into the chat.
• For Microsoft 365 Copilot Chat, store uploaded files in OneDrive for Business, where they can be deleted later.

However, the context only documents:

• Uploading files into Copilot Chat and Copilot in Edge.
• Copilot using those files for summarization, extraction, translation, and similar tasks.
• Troubleshooting issues with uploading files (supported formats, permissions, file location, file size/complexity).

It does not document:

• Copilot Chat creating and returning new .docx files as downloadable attachments or links.
• Any supported workflow where Copilot Chat “publishes” a newly generated Word document back to the user as a file.
• Any known issue or fix related to the specific error message “Object reference not set to an instance of an object” in this context.

Based on the available information, the only supported and documented file‑related capabilities are upload, analysis, and use of existing files, not guaranteed generation and delivery of new Word documents as attachments from Copilot Chat. For now, the reliable path is to:

• Upload existing documents for analysis and transformation.
• Copy generated content from the chat and paste it into Word manually to create .docx files.

If the error persists and blocks critical workflows, the appropriate next step is to open a support case through the Microsoft 365 admin center so the issue (including the null‑reference error) can be investigated by product support.

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References:

• Frequently asked questions about Copilot Chat
• File formats supported by Microsoft 365 Copilot
• Manage Microsoft 365 Copilot Chat
• Using Microsoft Copilot in Edge at work
• Get started with Word, Excel, and PowerPoint Agents in Microsoft 365 Copilot