[BUG] Claude Desktop 1.0.734: MCP servers fail to initialize - 'Cannot read properties of undefined (reading cmd)'

Resolved 💬 26 comments Opened Nov 15, 2025 by vimholic Closed Nov 30, 2025

💡 Likely answer: A maintainer (catherinewu, contributor) responded on this thread — see the highlighted reply below.

Bug Description

Claude Desktop version 1.0.734 fails to initialize all MCP servers with a JavaScript runtime error, making MCP functionality completely unusable.

Error Message

Cannot read properties of undefined (reading 'cmd')

Stack Trace:

TypeError: Cannot read properties of undefined (reading 'cmd')
    at C:\Users\primus\AppData\Local\AnthropicClaude\app-1.0.734\resources\app.asar\.vite\build\index.js:211:8256
    at async C:\Users\primus\AppData\Local\AnthropicClaude\app-1.0.734\resources\app.asar\.vite\build\index.js:211:6757

Environment

OS: Windows 11
Claude Desktop Version: 1.0.734 (released 2025-11-15)
Previous Working Version: 1.0.332 (released 2025-11-06)
Log File: %APPDATA%\Claude\logs\mcp-server-*.log

Steps to Reproduce

Install Claude Desktop 1.0.734 (latest version as of 2025-11-15)
Configure any MCP server in %APPDATA%\Claude\claude_desktop_config.json:

``json { "mcpServers": { "cdn-billing": { "command": "python", "args": ["C:\\path\\to\\mcp_proxy.py"], "env": { "MCP_HOST": "localhost", "MCP_PORT": "8765" } } } }``

Restart Claude Desktop
Check logs at %APPDATA%\Claude\logs\mcp-server-cdn-billing.log

Expected Behavior

MCP server should initialize successfully and tools should be available in Claude Desktop.

Actual Behavior

MCP server initialization fails immediately
Error appears in logs: Cannot read properties of undefined (reading 'cmd')
No MCP tools are available
Same configuration worked perfectly in version 1.0.332

Impact

CRITICAL: All MCP servers fail to initialize in version 1.0.734

This affects:

All users who updated to 1.0.734
All new installations (1.0.734 is currently the latest distributed version)
Any custom MCP servers regardless of configuration

Workaround

Downgrade to version 1.0.332:

PowerShell:

# Stop Claude Desktop
taskkill /F /IM claude.exe /T

# Remove broken version
Remove-Item -Path "$env:LOCALAPPDATA\AnthropicClaude\app-1.0.734" -Recurse -Force
Remove-Item -Path "$env:LOCALAPPDATA\AnthropicClaude\packages\AnthropicClaude-1.0.734.nupkg" -Force

# Disable auto-update
Rename-Item -Path "$env:LOCALAPPDATA\AnthropicClaude\Update.exe" -NewName "Update.exe.disabled"

# Start working version
Start-Process "$env:LOCALAPPDATA\AnthropicClaude\app-1.0.332\claude.exe"

Additional Context

This bug was discovered while deploying MCP servers to production
Version 1.0.734 is still being distributed as the latest version at https://downloads.claude.ai/releases/win32/x64/RELEASES
The error occurs during MCP configuration parsing, suggesting a regression in the configuration validation code
No configuration changes work - the bug affects all MCP server configurations
Verified that 1.0.332 works with identical configuration

Severity

High - Breaks all MCP functionality for Windows users on latest version

View original on GitHub ↗

25 Comments

survivalbrainai · 8 months ago

I can confirm same issue as described.

B-ki · 8 months ago

I can also confirm this issue.

akoSiThaesler · 8 months ago

also having the same issue on my side

lrnzslrn83 · 8 months ago

Same Issue

bongole · 8 months ago

Same Issue

jamiabailey · 8 months ago

I can also confirm this issue. Happened as soon as Claude desktop upgraded (broke) and when downgrading it fixes it with exact MCP configuration json.

HappyNoodleBoyIHFAMB · 7 months ago

Can also confirm I am experiencing this issue.

polartulip · 7 months ago

+1 Confirm

austinherrema · 7 months ago

Same here. I just installed for the first time so the workaround of reverting to an older version does not work for me.

izibazi · 7 months ago

Same Issue Claude 1.0.734 (b8f837) 2025-11-14T18:56:13.000Z

VDVThomas · 7 months ago

Same issue.

danieljeannetot · 7 months ago

Same issue.
This is a new computer and I do not have access to previous version locally.
How can I downgrade without a local version available?

IgorFZ · 7 months ago

Same issue.

tomkless · 7 months ago

can confirm bug as well - same issue - downgrading workaround also confirmed as working

conradj5 · 7 months ago

Same issue. This is a new computer and I do not have access to previous version locally. How can I downgrade without a local version available?

Downgraded on Windows using winget

winget install -e --id Anthropic.Claude -v "1.0.332"

leoweb57 · 7 months ago

How can I disable auto update ?

davidcrossey · 7 months ago

Same issue. Had to downgrade, thanks @conradj5 for your tip!

bilotilvv · 7 months ago

Thanks @conradj5 for your tip! However, it does not work for me. I used this command:

winget install -e --id Anthropic.Claude -v "1.0.332" --uninstall-previous --no-upgrade --force

Also, I renamed the Update.exe to prevent the automaic update.

Rename-Item -Path "$env:LOCALAPPDATA\AnthropicClaude\Update.exe" -NewName "Update.exe.disabled"

> winget show Anthropic.Claude -v "1.0.332"
Found Claude [Anthropic.Claude]
Version: 1.0.332
Publisher: Anthropic PBC
Publisher Support Url: https://docs.google.com/document/d/11rLWQYaReoZrRaoyPU3_gbgmDgLOKBVjEa-lvPDiWXE/edit
Author: Anthropic PBC
Moniker: claude
Description: Your AI partner on desktop. Fast, focused, and designed for deep work.
License: Proprietary
Copyright: © 2025 Anthropic PBC
Purchase Url: https://www.anthropic.com/pricing
Tags:
  ai
  chatbot
  large-language-model
  llm
Installer:
  Installer Type: exe
  Installer Url: https://downloads.claude.ai/releases/win32/x64/1.0.332/Claude-b563c986e881440c8f6255bb65a677101ee38579.exe
  Installer SHA256: 82fbea295c365fca6c26a9b6f57abf66b365932360585701d037dbe1ae953b6a
  Offline Distribution Supported: true

catherinewu contributor · 7 months ago

Thanks for reporting. This seems like an issue with Claude Desktop and the Claude Desktop team will be releasing a hypothesized fix tomorrow. Closing since this is the Claude Code repo and I don't think this is an issue with Claude Code

MarshallOfSound · 7 months ago

Hey folks, thanks for reporting, as mentioned above we should have a hypothesized fix out for this soon.

To help us verify / identify the issue here, can someone who was experiencing this issue run where python in cmd or Get-Command python in powershell.

Also interested in the python3 variants.

leoweb57 · 7 months ago

Last Claude Desktop release 1.0.1307 fix it

joan-anthropic · 7 months ago

Hi all, we've released an update containing an expected fix, pls post here if you still encounter any issues. thanks!

bennyj1 · 7 months ago

New error:
Error: spawn uv ENOENT

vimholic · 7 months ago

Confirmed fixed in v1.0.1405!

Environment:

OS: Windows 11
Previous Version: 1.0.332 (downgraded due to bug)
Updated Version: 1.0.1405
Update Date: 2025-12-02

Test Results:

✅ MCP server initialization successful
✅ All MCP tools working as expected
✅ No more "Cannot read properties of undefined (reading 'cmd')" errors

Thank you for the quick fix! The update resolved the issue completely.

github-actions[bot] · 7 months ago

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.

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