claude_desktop_config.json Not Loading: How to Fix It (Windows, macOS, Linux)

If Claude Desktop seems to ignore claude_desktop_config.json, one of four things is wrong: you edited a different file, the JSON is invalid, your servers are not under the mcpServers key, or the app was never fully restarted. The fastest fix is to open the file through Settings > Developer > Edit Config, run it through a JSON validator, then quit Claude Desktop from the menu bar or system tray and open it again.

Checked against: the MCP local server guide, the MCP build-a-server tutorial, the MCP debugging guide and Claude Code issue #26073 on 2 November 2026. The GitHub issue is a user report. eSEOspace did not test on each OS.

What this error means

Claude Desktop reads its config once, when it starts. It looks for servers under a top-level mcpServers object. The build tutorial notes that MCP elements "will only show up in Claude for Desktop if at least one server is properly configured."

So "not loading" can mean the app never saw your edit, saw it but could not parse it, or parsed it and found no servers in the expected place. Each has a quick test.

Quick fix

1. Open the file from the app. Go to Settings > Developer > Edit Config. The local server guide says this "creates a new configuration file if one doesn't exist, or opens your existing configuration."
2. Validate the JSON. On macOS or Linux, run:

python3 -m json.tool ~/Library/Application\ Support/Claude/claude_desktop_config.json

It prints the file if valid, or the line and column of the first error. On Windows, PowerShell's Get-Content $env:APPDATA\Claude\claude_desktop_config.json -Raw | ConvertFrom-Json does the same job.

1. Check the shape. All servers go inside one mcpServers object:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/you/Desktop"]
    },
    "weather": {
      "command": "/Users/you/.local/bin/uv",
      "args": ["--directory", "/Users/you/weather", "run", "weather.py"]
    }
  }
}

1. Quit fully. On macOS use Cmd+Q. On Windows, right-click the Claude tray icon (it may be under hidden icons) and choose Quit. On Linux, quit from the tray or run pkill -f claude-desktop. These steps come from the build tutorial.
2. Reopen and check. Click the "Add files, connectors, and more" button in the chat box, hover over Connectors, and open Manage connectors.

You can also generate a clean file with the MCP config generator.

Fix by client / OS

macOS

The file is at ~/Library/Application Support/Claude/claude_desktop_config.json. The Library folder is hidden in Finder, which is one reason people edit the wrong file. Use Edit Config or the full path in Terminal. Full setup steps are in Claude Desktop MCP setup on Mac.

Windows

The documented path is %APPDATA%\Claude\claude_desktop_config.json. Inside JSON, every backslash in a path must be doubled: C:\\Users\\you\\Desktop. The build tutorial also allows forward slashes.

There is a known report of a second file. Claude Code issue #26073, opened in February 2026 and still open when checked, says that on an MSIX-packaged install, Edit Config opened %APPDATA%\Claude\claude_desktop_config.json while the app read a different copy inside the MSIX virtual file system, with "no error messages, no logs." A related report, issue #70393, gives that path as %LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\claude_desktop_config.json. If your edits never take effect on Windows, check whether that folder exists and compare the two files. See also Claude Desktop MCP setup on Windows.

Linux

The file is at ~/.config/Claude/claude_desktop_config.json, per the local server guide.

Claude Code users

Claude Code does not read this file for its own servers. You can import from it with claude mcp add-from-claude-desktop, which the Claude Code MCP docs say works only on macOS and WSL. Server names with characters other than letters, numbers, hyphens and underscores are skipped.

Where to find the logs

If the file loads but a server fails, the logs say why. The debugging guide gives ~/Library/Logs/Claude (macOS), %APPDATA%\Claude\logs (Windows) and ~/.config/Claude/logs (Linux). The guide says these logs capture "configuration issues" as well as connection events. If your server's name never appears in mcp.log, the app did not read your entry.

If it still fails

• The server appears but shows an error. The config loaded. Now fix the server. See MCP server not connecting in Claude Desktop.
• spawn npx ENOENT in the log. See spawn npx ENOENT.
• You want to know every file location. See Claude Desktop config file location.
• A server needs a secret. Put it under env for that server, and keep the file out of shared folders and repos.

For teams that need one approved config rolled out to many machines, our MCP readiness audit can help.

Frequently asked questions