Internal Error in Agent mode with Opus 4.8 High

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Getting Internal Error when using Agent mode with Opus 4.8 High model.

Error: “An unexpected error occurred on our servers. Please try again, or contact support if the issue persists.”

Request ID: 2a1b673b-d7a8-48bd-81cd-a21c8b336bb7

Steps to Reproduce

  1. Open Cursor IDE
  2. Open Agent mode (Ask tab)
  3. Select model: Opus 4.8 High
  4. Type any question and press Enter
  5. Get “Internal Error” message

Expected Behavior

Agent should respond normally without error.

Operating System

Windows 10/11

Version Information

IDE: Cursor (latest)
CLI Version 2026.01.17-d239e66
OS: Windows 11

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

5

Hey there!

I can’t see this Request ID in our backend, which means the request might never have made it off your machine.

  • Try running Network Diagnostics in Cursor to see if you get a specific error, and also try changing the HTTP Compatibility Mode to HTTP 1.1 if it’s set to HTTP 2.
  • Do any other models work?