[SOLVED] MCP Servers can cause issue with Agent Mode

[husniadil]

Hi,

I have issue when working with Cursor, it has been happening since one day ago. Not sure what’s happening.

It says that it cannot connect to Anthropic, I tried to switch to gpt-4o and the same thing happened.

One workaround that worked for me is to reload Cursor (Developer: Reload Window) and/or Restart/Reopen Cursor.

What I have done to hopefully solve the issue by myself:

1. Restart wifi
2. Make sure it is not connected to any other networks like VPN
3. Speed test (no issue), other websites load well
4. Restart Mac

None of above have worked. I have searched through forum and doesn’t seem a global issue.

Check the GIF video below:

Please help!

[deanrie]

Hey, check if there are any errors in the DevTools panel when this error occurs.

[husniadil]

I have uninstalled Cursor, downloaded again from the web and installed it again. The issue still persists.

This is when showing the Cannot connect to Anthropic:

After I did reload using Developer: Reload Window, and the agent successfully responded, it showed this:

Then here when I tried to chat with the agent again:

[husniadil]

I also have tried to disable all extensions, the same issue still happening

[husniadil]

Hi, I just disabled some of the MCP servers installed, and now it’s working fine. But I think Cursor should give us a more clear error message since it’s kind of misleading.

@deanrie Anyway, thank you for pointing out the DevTool!

[alioshr]

I have faced the same thing with an MCP server that demands resources (Resources - Model Context Protocol). I had to stop using it. I use it with Cline, then bridge the stuff through another mcp server to the agent in cursor.

The root cause is that Cursor has a limited MCP support and does not handle errors gracefully.