Grok-code-fast-1 and code-supernova giving empty responses

[slikc]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

On my M3 macbook air, the grok-code-fast-1 and code-supernova models both provide empty responses, whilst they work fine from my windows PC. in the dashboard all requests are marked as fails. they sometimes work, but it’s either random or having just restarted the IDE, for one message.

I’ve tried reinstalling - nothing changes

been going on for a few days and is pretty irritating

Steps to Reproduce

possibly try the same device type? I’m not sure it’s possible as it seems to be limited to my device, have asked others and found no one with the same issue.

Expected Behavior

AI should respond correctly.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.6.42
VSCode Version: 1.99.3
Commit: 5911e9593196a000b1c00553aaf03b0b32042b90
Date: 2025-09-20T17:16:56.346Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 25.0.0

For AI issues: which model did you use?

grok-code-fast-1
code-supernova

For AI issues: add Request ID with privacy disabled

RequestID: f6f40674-40fe-4687-bc23-54ad08b611bd

Additional Information

grok-code-fast-1 worked for me during the initial free period, then stopped working afterwards, and since has never worked fully - code-supernova has never worked

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

[slikc]

following up, just noticed they both work in ask mode, just not agent mode.

[deanrie]

Hey, thanks for the report. Could you let me know if you’re using any MCP servers? If so, please try disabling them and check if that resolves the issue.

[slikc]

yep, that was it thanks, it was the posthog MCP which seems to break both of them, not sure if that’s something you can look into or not

[jaronheard]

I can validate that enabling Posthog MCP breaks both of these models, and that this issue currently persists.