Background agents fail immediatly with latest 1.3

Support Bug Reports
1

Describe the Bug

Just updated cursor

Background agents fail immediately. I’ve having problems with random disconnections of agents so I think that I have some sort of network corner case that cursor doesn’t handle that well. I’m on Starlink btw with Windows 10.

Background agent creation would sometimes succeed, but mostly fail. The 1.30 version they fail immediatly instead of 7 minutes of doing stalling.

Failing fast is definatly an improvement over failing in 7 minutes. But I still can’t use the agents.

Here are some failing requests

bc-1e67ac53-9b4e-42d1-8949-d3e4284866b7
bc-aaf7fbe3-d913-4d74-a93d-d4412389d4cb

Steps to Reproduce

CTRL+E

Select claude hauiku (just writing a design document, no code changes) then hit submit. Fails immediately.

Expected Behavior

To not fail and for the background agent to start working correctly.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.3.6 (user setup)
VSCode Version: 1.99.3
Commit: 68b8fe7396ea37d8acdaaaa08ba316ba359a4160
Date: 2025-07-30T18:17:09.810Z
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Windows_NT x64 10.0.19045

2

Hey, we released a new update 1.3.7. Try updating and let me know if the issue persists.

3

Nope, still get the error.

I updated. Then hit ctrl-E. Submit my request. Fails immediatly. Here’s the request id of the latest failure:

bc-44a7726f-55ae-4eb7-a7ca-82a09342714f

4

Looking into this one

5

The problem is the model here - looks like Claude Haiku was selected. Are you able to try a recommended model? I am looking into how that is possible.

6

Looks like this would have to be added via “add models” - but Background Agents don’t support this model.

7

That looks like the cause.

Prompt: “Write hello world to the console.”

Sonnet Opus MAX: No instant fail
O3 MAX: No instant fail
Claude 3.5 MAX: No instant fail

8

Sonnet model always fails for me in background agent. Opus doesn’t but I don’t need such an expensive model.

9

No resolution?