Troubleshooting hub

Claude Code error fixes

Fix Claude Code native Windows MCP launch, Playwright reconnect, NPX, and plugin errors.

7source-linked fixes

Start with the exact error, then confirm the operating system, client, and version. Do not apply a workaround solely because the product name matches.

Checking an MCP configuration? Validate your MCP configuration before changing packages, or give your agent the MCP debugging triage skill.

Claude CodeConfirmed workaround

Claude Code Playwright MCP fails after /c becomes C:/

Failed to reconnect to plugin:playwright:playwright

Fix Claude Code Playwright MCP -32000 and Failed to reconnect when Windows /c is rewritten to C:/ in plugin configuration.

Open fix →

Claude CodeOpen issue

Claude Code WSL tries to create /mnt/c/Users/.claude

bwrap: Can't mkdir /mnt/c/Users/.claude: Permission denied

Diagnose Claude Code WSL sandbox failures that try to create /mnt/c/Users/.claude after managed settings are enabled.

Open fix →

Claude CodePartial workaround

Claude Desktop passes a literal ${VAR} to an MCP server

MCP server receives the literal string ${VAR}

Diagnose Claude Desktop on Windows when an MCP env value stays as a literal ${VAR}, while the same user-scope configuration expands in Claude Code CLI.

Open fix →

Claude CodePartial workaround

Claude Code startup fails with ERR_SOCKET_CLOSED behind a proxy

Failed to connect to api.anthropic.com: ERR_SOCKET_CLOSED

Fix the Claude Code 2.1.220 startup preflight regression that returns ERR_SOCKET_CLOSED behind a working corporate HTTPS proxy.

Open fix →

Claude CodePartial workaround

Claude Desktop cancels MCP initialize after 60 seconds

Message from client: method="notifications/cancelled"

Diagnose Claude Desktop MCP initialize cancellations when an npx, uvx, or pipx package runner spends more than 60 seconds resolving dependencies.

Open fix →

Claude CodeOpen issue

Claude Desktop MCP tools fail with side_channel_waiting_key_absent

side_channel_waiting_key_absent

Diagnose Claude Desktop when every MCP tool shows Failed to call tool but server logs succeed and tool_result returns side_channel_waiting_key_absent.

Open fix →

Claude CodeConfirmed workaround

Claude Code MCP spawn npx ENOENT on Windows

SPAWN ERROR: ENOENT spawn npx ENOENT

Fix Claude Code MCP plugins that fail with SPAWN ERROR: ENOENT spawn npx ENOENT on native Windows.

Open fix →