can not connect mcp tool (it was working earlier)

[vmakarevich-prog]

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.)
⚠️ WARNING ⚠️ If you have sensitive data in your workflow (like API keys), please remove it before sharing.

{
"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

[n8n-assistant]

Hey @vmakarevich-prog,

Thank you for reaching out! We’ve received your issue and are looking into it. To help us track this internally, we’ve created a Linear ticket with the reference: "GHC-8654".

We’ll keep you updated as we make progress, but if you have any additional details or context to share, feel free to add them here - it’s always helpful!

Thanks for your patience and for bringing this to our attention.

---

For INTERNAL use only: GHC-8654

[sinehypernova-0718]

Hey @vmakarevich-prog, could you share the exact error message that appears in the popup window when the connection fails? It'll may help to narrow down the issue.

[vmakarevich-prog]

its not exactly about error fallback. atlassian updaten endpoints for mcp and now it can not connect to n8n. their unswer: Our team has tested n8n using api tokens which works, but the OAuth 2.1 flow with DCR does not seem to be working with n8n. That said, we recommend following up with n8n as we have observed they’ve had a few issues with their DCR flow based on recent github issues.

[sinehypernova-0718]

Hey, this looks like the same missing resource parameter issue in #30733 I've been working on in #30924. My PR fixes exactly that, might work for this too. If you get a chance to test it, it would be great and if it still doesn't connect, let me know and I'd love to dig a bit deeper onto this.

[vmakarevich-prog]

thanks, will test it

[sinehypernova-0718]

Hii! @vmakarevich-prog Have you tested it? Did it work for you? The PR has been approved. If you can confirm, then I will link this issue too :)

[vmakarevich-prog]

hi. we tried to instal 2.26.3 update, but it doesn't help

[sinehypernova-0718]

Hii! @vmakarevich-prog My PR #30924 got merged but haven't got released yet. But, as you can see, the maintainer's have linked a PR to close this issue in #32300. So, the fix for this might land in the next release probably.
Thanks! 🙂