[BUG] Cowork: project creation fails with generic error when name contains special characters (e.g. `|`)

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?

When creating a new project in Cowork, using certain special characters in the project name (e.g. pipe |) causes creation to fail with a generic "Failed to create project. You can try again" message. The error gives no indication that the problem is an invalid character in the name — users are left guessing whether it's a server issue, a network issue, or their own fault.

What Should Happen?

Expected: Either (a) accept the character, or (b) show a specific validation error like "Project names cannot contain: | / \\ : * ? \" < >" before submission — or reject the character inline as the user types.

Error Messages/Logs

**Observed:** Generic "Failed to create project. You can try again" toast. Project is not created. Retrying with the same name reproduces the error indefinitely.

Steps to Reproduce

Steps to Reproduce

1. Open Claude Desktop → Cowork → Projects
2. Click "Create new project"
3. Enter a name containing a pipe character, e.g. Test | Project
4. Submit

Observed: Generic "Failed to create project. You can try again" toast. Project is not created. Retrying with the same name reproduces the error indefinitely.

Expected: Either (a) accept the character, or (b) show a specific validation error like "Project names cannot contain: | / \\ : * ? \" < >" before submission — or reject the character inline as the user types.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Version 1.3109.0 (35cbf6) [Claude-desktop client]

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

What's Wrong?

When creating a new project in Cowork, using certain special characters in the project name (e.g. pipe |) causes creation to fail with a generic "Failed to create project. You can try again" message. The error gives no indication that the problem is an invalid character in the name — users are left guessing whether it's a server issue, a network issue, or their own fault.

Steps to Reproduce

1. Open Claude Desktop → Cowork → Projects
2. Click "Create new project"
3. Enter a name containing a pipe character, e.g. Test | Project
4. Submit

Observed: Generic "Failed to create project. You can try again" toast. Project is not created. Retrying with the same name reproduces the error indefinitely.

Expected: Either (a) accept the character, or (b) show a specific validation error like "Project names cannot contain: | / \\ : * ? \" < >" before submission — or reject the character inline as the user types.

Environment

• Claude Desktop version: [fill in — Settings → About]
• OS: [fill in — e.g. Windows 11 / macOS 14]
• Plan: [Pro / Max / Team]

Why this matters

The error message suggests a transient issue ("you can try again"), so users retry with the same name instead of editing it. I only found the cause by trial and error. A specific validation message would save real time and reduce support load.

Suggested fix

• Validate project name client-side against the allowed character set
• Show the specific invalid character(s) in the error
• Or: sanitize the name automatically and warn the user