Symptoms

• Unity MCP error: “Failed to start Claude CLI. dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.71.dylib …”
• Running claude in Terminal fails with missing libicui18n.xx.dylib.

Cause

• Homebrew Node (or the claude binary) was linked against an ICU version that’s no longer installed; dyld can’t find that dylib.

Fix options (pick one)

• Reinstall Homebrew Node (relinks to current ICU), then reinstall CLI:

  brew update
  brew reinstall node
  npm uninstall -g @anthropic-ai/claude-code
  npm install -g @anthropic-ai/claude-code

• Use NVM Node (avoids Homebrew ICU churn):

  nvm install --lts
  nvm use --lts
  npm install -g @anthropic-ai/claude-code
  # Unity MCP → Claude Code → Choose Claude Location → ~/.nvm/versions/node/<ver>/bin/claude

• Use the native installer (puts claude in a stable path):

  # macOS/Linux
  curl -fsSL https://claude.ai/install.sh | bash
  # Unity MCP → Claude Code → Choose Claude Location → /opt/homebrew/bin/claude or ~/.local/bin/claude

After fixing

• In Unity MCP (Claude Code), click “Choose Claude Location” and select the working claude binary, then Register again.

More details

• See: Troubleshooting Unity MCP and Claude Code

Q: Unity can’t find claude even though Terminal can.

• A: macOS apps launched from Finder/Hub don’t inherit your shell PATH. In the Unity MCP window, click “Choose Claude Location” and select the absolute path (e.g., /opt/homebrew/bin/claude or ~/.nvm/versions/node/<ver>/bin/claude).

Q: I installed via NVM; where is claude?

• A: Typically ~/.nvm/versions/node/<ver>/bin/claude. Our UI also scans NVM versions and you can browse to it via “Choose Claude Location”.

Q: The Register button says “Claude Not Found”.

• A: Install the CLI or set the path. Click the orange “[HELP]” link in the Unity MCP window for step‑by‑step install instructions, then choose the binary location.

• A: Start a new chat, the bad chat didn't 'take' the MCP server configuration.