[BUG] Desktop app (Windows): SendUserFile PDF card has no download/share button on one PC, while the same call shows it on another PC

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In the Claude desktop app for Windows (Code tab), when Claude sends a PDF with the SendUserFile tool, the file card in the conversation has no download/share button at the top-right corner. Right-clicking the card only shows "Attach as context", "Copy" and "Show in Explorer". There is no way to download the file or share it to another device from the card.

What Should Happen?

On my other Windows PC (also updated to the latest app), the same kind of card shows a share/download button at the top-right corner, opposite the "PDF" badge. I expect the same button on this PC.

Error Messages/Logs

Steps to Reproduce

1. Open a session in the Code tab of the Claude desktop app on Windows.
2. Ask Claude to create a PDF and send it (Claude calls SendUserFile with display="attach", status="normal").
3. Look at the file card in the conversation: there is no download/share button at the top-right corner.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Desktop app 2.19675.0 / claude --version: 2.1.270 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Same PDF (281.9KB) was sent in 7 ways on the affected PC (Windows 11 Pro 10.0.26300). The button never appeared:

1. display="attach", status="normal", session with no folder, file in the session's scratch workspace
2. display unset, status="normal", same location
3. display="render", status="normal", same location
4. display unset, status="normal", file in a normal folder (Documents) added to the session
5. display unset, status="normal", after moving the session itself into that folder
6. display unset, status="proactive", same
7. display="attach", status="normal", session in that folder (identical to the call used on the PC where the button appears)

On the PC where the button appears: SendUserFile with display="attach", status="normal". The button appears for files inside the session's working directory and also for files outside it.

Possibly related: #95365, #86337

<img width="395" height="286" alt="Image" src="https://github.com/user-attachments/assets/7e3fcc57-3027-4f91-b573-9b0900c9850e" />