[BUG] OAuth MCP reconnection fails after successful authentication. "Authentication successful, but server reconnection failed" Version: 2.1.71
Status Closed — not planned
Reported on v2.1.71
Maintainer reply None cached
Activity 6 comments · opened Mar 9, 2026 · closed Apr 6, 2026
Preflight Checklist
- [x] I have searched existing issues and this hasn't been reported yet
- [x] This is a single bug report (please file separate reports for different bugs)
- [x] I am using the latest version of Claude Code
What's Wrong?
OAuth MCP reconnection fails after successful authentication.
"Authentication successful, but server reconnection failed"
Version: 2.1.71
What Should Happen?
OAuth MCP reconnection fails after successful authentication.
"Authentication successful, but server reconnection failed"
Version: 2.1.71
Error Messages/Logs
Steps to Reproduce
OAuth MCP reconnection fails after successful authentication.
"Authentication successful, but server reconnection failed"
Version: 2.1.71
Claude Model
None
Is this a regression?
Yes, this worked in a previous version
Last Working Version
_No response_
Claude Code Version
Version: 2.1.71
Platform
Anthropic API
Operating System
macOS
Terminal/Shell
Terminal.app (macOS)
Additional Information
_No response_
6 Comments
I'm hitting the same issue. Here's a detailed diagnosis from my end.
Environment: Claude Code 2.1.71, macOS Darwin 25.1.0, zsh
Server config: Added via claude mcp add --transport http miro https://mcp.miro.com, stored in
~/.claude.json.
What happens: Browser OAuth completes, Miro authorises successfully, then Claude Code shows
"Authentication successful, but server reconnection failed." Inspecting the macOS Keychain (security
find-generic-password -s "Claude Code-credentials" -w) shows either no Miro entry in mcpOAuth, or an
entry with an empty access token and expiresAt: 0.
Other MCP servers work fine. GitHub, Figma, Notion, and Google Drive all have valid tokens in the same
keychain entry. The problem is specific to Miro.
What I've tried (all failed):
Possible root cause: This may be related to #30337 (macOS Keychain 4096-byte line buffer). I already
have four OAuth tokens stored (GitHub, Figma, Notion, Google Drive). Adding Miro's token could push the
total credential blob past the 4096-byte limit, causing a silent write failure. This would explain why
auth succeeds but the token never reaches the keychain.
Support reference: 739f414141bf8b41
Looks like a similar to mine which I logged here: https://github.com/anthropics/claude-code/issues/32494.
Closing for now — inactive for too long. Please open a new issue if this is still relevant.
Are you closing a BUG? Are you serious guys?
Experiencing the same issue. I'm on version 2.1.92, macOS Tahoe 26.41.
I have both Honeycomb and Atlassian. Honeycomb works fine, while Atlassian keeps failing to connect although the authentication succeeded.
This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.