[Bug] MCP server authentication returns HTTP 431 error

Bug Description
All MCP server auth , response This page isn’t working
If the problem continues, contact the site owner.
HTTP ERROR 431 (browser restart!

Environment Info

• Platform: linux
• Terminal: cursor
• Version: 2.1.141
• Feedback ID: 899ce9e4-6d81-4d84-80f5-ad547be38b82

Errors

[]


This page isn’t working
If the problem continues, contact the site owner.
HTTP ERROR 431


• New session claude code
• New session chrome

`
Diagnostics
├ Currently running: native (2.1.141)
├ Commit: 4f4623ddd339
├ Platform: linux-x64
├ Path: /home/mika/.local/share/claude/versions/2.1.141
├ Config install method: native
└ Search: OK (bundled)

⚠ Multiple installations found
├ npm-global at /home/mika/.nvm/versions/node/v21.7.2/bin/claude
└ native at /home/mika/.local/bin/claude

⚠ Leftover npm global installation at /home/mika/.nvm/versions/node/v21.7.2/bin/claude
└ Run: npm -g uninstall @anthropic-ai/claude-code

Updates
├ Auto-updates: enabled
├ Auto-update channel: latest
├ Stable version: 2.1.128
└ Latest version: 2.1.141

Background server
└ Status: not running
└ Mode: ephemeral
└ See claude daemon status for details

Version locks
└ 2.1.140: PID 2259717 (running)
`

Authorization isn't working; there's no MCP server.