BUG: new UI prevents Cursor from authenticating with all MCP servers

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The new customize UI as noted in 167704 is badly broken and refuses to display project’s MCP servers.

This also means: authentication is now impossible. There is no other way to get cursor to authenticate - now that you’ve deleted the ‘authenticate’ button we cannot add or use any new MCP servers.

I cannot find a workaround - what am I missing?

Steps to Reproduce

Install current version

Operating System

Windows 10/11

Version Information

Version: 3.15.19 (user setup)
VS Code Extension API: 1.128.0
Commit: de07bee81cefe43461ebf4f40c3d2d78d15052a0
Date: 2026-08-11T05:22:54.627Z
Layout: IDE
Build Type: Stable
Release Track: Default
Electron: 40.10.3
Chromium: 144.0.7559.236
Node.js: 24.15.0
V8: 14.4.258.32-electron.0
xterm.js: 6.1.0-beta.291
OS: Windows_NT x64 10.0.26200

Does this stop you from using Cursor

Yes - Cursor is unusable

7

Hey there! This isn’t intended behavior, and it’s not something you misconfigured.

The Authenticate action wasn’t removed; in the new Customize view it lives inline on each MCP server’s row. It only looks gone because the row itself isn’t rendering. This happens with a multi-root .code-workspace: servers from a folder’s .cursor/mcp.json don’t list under Customize → MCPs.

Two ways to unblock now:

  1. Open the folder with .cursor/mcp.json directly (File → Open Folder) instead of the .code-workspace - the servers show up with their Authenticate button.
  2. Or move that server into your user-level ~/.cursor/mcp.json, which isn’t affected.

We’ve let the team know and this is an issue we’re tracking; a fix is on the way in an upcoming update, and I’ll follow up here when it lands.

Are you on a multi-root .code-workspace or a single folder? If it’s a single folder on 3.15.19 and servers still don’t show, that’d be a different case I’d want to dig into.

8

No. That is incorrect.

I’ve never used a ‘code workspace’, your bugs with workspaces are something different.

Copying everything to the existing ~/.cursor has no effect, neither in Windows (the user home equivalent) nor in linux.

All projects run in devcontainers, so this may be an extra bug you’ve created with containers - but it has the same characteristics as your other bugs here.

10

HI @A_A6

We shipped some fixes in v3.16 – can you check if you still face the issue on this version?

13

I found a hack to workaround the bug you guys added to the Cursor installer, and got 3.17 to install.

MCP servers still completely blocked - by Cursor - with forced advert for your Marketplace instead.

Cursor agent, when interrogated, says:

ME: “what mcp servers can you see right now?”

CURSORGROK4.6: "I can see one MCP server right now:

cursor-ide-browser — ready
Cursor’s built-in browser tab plus Chrome DevTools Protocol tools. The catalog lists it as available, but no tools are showing on it in this session.

That’s the full MCP catalog I have access to at the moment. If you expected others (Datadog, Linear, Slack, etc.), they aren’t connected here."

ME: “what about the ones in mcp.json?”

CURSORGROK4.6: "I’ll look up mcp.json and compare it to the servers I can actually use.

There are two servers in .cursor/mcp.json. None of them showed up in the live MCP catalog I can call.

Name URL
airtable https://mcp.airtable.com/mcp
granola https://mcp.granola.ai/mcp

What I can actually use right now is still only cursor-ide-browser. The mcp.json entries are configured in the project, but they are not connected in this session — likely not running, not authenticated, or not loaded by Cursor for this chat."

This is really basic: you just need to remove the advertising for your Marketplace and reinstate the simple, effective, working “list the MCP servers and configure them” control.

14

More than 2 weeks, still no MCP access in Cursor at all. Some projects have MCP, others have none. No workaround from Cursor support.

I work with multiple orgs, and some of them had already moved off Cursor because of the bugs at start of this year, I’m pretty sure this will push the rest of them off. How can you leave MCP broken? Literally every serious AI using org is dependent on this all day every day!

19

Hi @A_A6, thanks for sticking with this. MCP is working on 3.17 for most setups, so we need to pin down what’s different about yours.

I’ve created a sample project using a devcontainer that, when launched in Cursor, shows the MCP servers. (They’re blocked due to some admin settings on the team I’m logged into, but they’re definitely registered!)

Screenshot 2026-08-27 at 17.23.46
Screenshot 2026-08-27 at 17.23.461920×926 65.3 KB

Could you check whether you see these MCP servers as well?

20

As per all the other reports on these forums: some projects work, others do not.

If I open your project and it works, that tells us … what, exactly?

I can already open a project that works. I have cloned mcp settings between broken and working projects but the broken project is still broken.

I have traced this in detail (even hacking cursor internals to try to find the cause). The cause is clearly a bug internally in how the ‘new’ code in cursor builds its map of what servers exist.

22

FYI the only way I can get any work done on most projects is to downgrade to Cursor v3.8.11

Even the latest 3.8.x release (the only one offered on download page) is broken, because you remote-forced clients that dont have this bug to have this bug (feature flags?) – e.g. fresh installing 3.8.24 that didnt have this functionality it … magically has the functionality.

But I was able to find a download link for 3.8.11, which works 100% for all projects, because it predates the code change you made where you broke it.

I recommend taking a delta between that code and the new code and asking CursorGrok to look for the source of the bug. Tell it to read the source code only - it’s pretty good at discovering these bugs directly.