Cursor MCP server connection failed: 6 fixes for stdio and SSE errors
Cursor's MCP panel hides the real error behind "Client closed". Read MCP Logs, reproduce the command by hand, fix the config, restart Cursor.
Topic
AI Coding
Cursor, Claude Code, Copilot, Aider
Fix Cursor 401 Unauthorized User API Key on Overridden OpenAI Base URL
With Override OpenAI Base URL on, Cursor forwards the OpenAI API Key field's value to your endpoint; the 401 is that endpoint rejecting it. Fix the key pair, plus the two documented cases no key can fix.
How to Fix Cursor waitForProviderRegistration Timeout
Fix Cursor's waitForProviderRegistration timeout by locating the failing extension host, then repairing the remote server or desktop install with evidence.
How to Fix Cursor Extension Host Timeout (deadline_exceeded)
A code-specific fix for Cursor's ERROR_EXTENSION_HOST_TIMEOUT and deadline_exceeded message, with extension isolation, process checks, and repair steps.
How to Fix Cursor Agent Execution Backend Unavailable in WSL
A WSL-specific checklist for Cursor's Execution backend unavailable error, including the duplicate extension trap, reset command, and log checks.
Claude Code "advisor tool is unavailable" with Fable 5: workaround
The Fable 5 advisor fails on the first call in every session. Here is why it happens and the only workaround in v2.1.198.
Fix Claude Code 'Tool Call Could Not Be Parsed' (Retry Also Failed)
The partial-JSON parser chokes on CJK characters in tool-call arguments. Start a new session in English and keep tool-call args in ASCII.
Claude Code AskUserQuestion "No Response After 60s": How to Fix the AFK Timeout
Why Claude Code's AskUserQuestion silently answers itself after 60 seconds, and the version and config fix - plus the terminal-focus gotcha most write-ups skip.
How to Install Claude Code on macOS, Linux, and Windows
One native-installer command per shell, the Windows PowerShell-vs-CMD gotcha, and how to verify the install actually worked.
How Claude Code Plan Mode Works (and When to Use It)
Plan mode restricts Claude Code to read-only research until you approve its plan - here's the exact permission model, the keyboard shortcut, and when the extra review step is worth the friction.