n8n - 💡(How to fix) Fix can not connect mcp tool (it was working earlier)

Describe the problem/error/question

OAuth 2.1 in atlassian mcp does not work

What is the error message (if any)?

Please share your workflow/screenshots/recording

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)
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{ "nodes": [ { "parameters": { "endpointUrl": "https://mcp.atlassian.com/v1/mcp/authv2", "include": "selected", "includeTools": [ "getConfluencePage", "getConfluenceSpaces", "getPagesInConfluenceSpace", "getConfluencePageFooterComments", "getConfluencePageInlineComments", "getConfluenceCommentChildren", "getConfluencePageDescendants", "createConfluenceFooterComment", "createConfluenceInlineComment", "getJiraIssue", "getTransitionsForJiraIssue", "getJiraIssueRemoteIssueLinks", "getVisibleJiraProjects", "getJiraProjectIssueTypesMetadata", "getJiraIssueTypeMetaWithFields", "searchJiraIssuesUsingJql", "getIssueLinkTypes", "searchAtlassian", "fetchAtlassian", "searchConfluenceUsingCql", "getAccessibleAtlassianResources", "search", "fetch" ], "options": { "timeout": 60000 } }, "type": "@n8n/n8n-nodes-langchain.mcpClientTool", "typeVersion": 1.2, "position": [ 1600, -512 ], "id": "7e7df541-8b32-4c43-a8af-ae95191ea051", "name": "MCP Client" } ], "connections": { "MCP Client": { "ai_tool": [ [] ] } }, "pinData": {}, "meta": { "instanceId": "ac834beddc493d16f581bd66eee401b4881cb13b3d1e83721af62f1b82ec96c5" } }

Share the output returned by the last node

Debug info

core

• n8nVersion: 2.18.6
• platform: docker (self-hosted)
• nodeJsVersion: 24.14.1
• nodeEnv: production
• database: postgres
• executionMode: scaling (single-main)
• concurrency: -1
• license: enterprise (production)

storage

• success: all
• error: all
• progress: false
• manual: true
• binaryMode: database

pruning

• enabled: true
• maxAge: 336 hours
• maxCount: 10000 executions

client

• userAgent: mozilla/5.0 (windows nt 10.0; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/150.0.0.0 safari/537.36
• isTouchDevice: false

Generated at: 2026-06-08T03:25:57.799Z