[BUG] Cowork Project "Add folder" button permanently greyed out on Windows

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?

"Add folder" button in Cowork Project is permanently greyed out
and cannot be clicked at all on Windows.

Note: Unable to use the in-app "Get Help" support channel
(ERR_TIMED_OUT on api-iam.intercom.io — likely a regional
network issue in Vietnam), hence reporting via GitHub.

What Should Happen?

The "Add folder" button appears disabled (greyed out) in Cowork Projects.
No dialog opens when attempting to click it. Tried restarting both the app
and the machine — issue persists. The button is unresponsive before any
folder selection, so this is not related to folder location (C:\ vs D:\).

Error Messages/Logs

Failed to load resource: the server responded with a status of 400 ()
c0826ec51-CDunXp37.js:2 [MCP] [AutoSyncConnectorsToSession] Syncing 3 enabled MCP tool(s) to session cse_011KRujDLL6pMJqVnPgtY6ox
c0826ec51-CDunXp37.js:2 [MCP] [AutoSyncConnectorsToSession] Syncing 0 remote server(s) to session cse_011KRujDLL6pMJqVnPgtY6ox: (none)

Steps to Reproduce

1. Open Claude Desktop on Windows (latest version)
2. Go to Cowork
3. Create a new Project or open an existing one
4. Observe "Add folder" button — it is greyed out and unclickable

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude 1.20186.1 (df1d8a) 2026-07-10T21:55:12.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_