> For the complete documentation index, see [llms.txt](https://docs.mobb.ai/mobb-user-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mobb.ai/mobb-user-docs/getting-started/mobb-vibe-shield-mvs/troubleshooting-guide.md).

# Troubleshooting Guide

### Issue: MCP startup failed with "connection closed" error

**Symptoms:**

* Mobb Vibe Shield (MCP) client fails to start with error: `MCP startup failed: handshaking with MCP server failed: connection closed: initialize response`

**Resolution:**

This is typically caused by corrupted npm cache files in the npx directory. To resolve:

1. Navigate to your npm cache directory:
   * On macOS/Linux: `~/.npm/_npx/`
   * On Windows: `%USERPROFILE%\.npm\_npx\`
2. Delete all folders under the `_npx` directory
3. Retry the MCP client startup