Cursor says that the connection failed and blames my internet connection. If I try again then Cursor obstinately insists that my internet is broken. There is nothing wrong with my internet connection and other tabs in Cursor work just fine.
Steps to Reproduce
It happens a lot but I don’t have steps to reproduce it. It usually happens after a fairly lengthy request.
Expected Behavior
I expect Cursor to give a sensible error, or even better to let me try again.
Operating System
Windows 10/11
Current Cursor Version (Menu → About Cursor → Copy)
Cursor Settings → Network → Run Diagnostics, and share a screenshot of the results
Help → Toggle Developer Tools → Console, reproduce the issue and share a screenshot of the red errors (especially lines with “ConnectError” or “Serialization error”)
Check extensions:
Run cursor --disable-extensions in a terminal and see if that helps
If it helps, disable extensions one by one: Settings → Extensions
Thanks for the screenshots. I see a few possible issues:
CodeRabbit is an AI code review tool, and it can conflict with Cursor AI during long operations.
Please check these in order:
Disable CodeRabbit and see if the issue goes away. This extension is the most likely to conflict with Cursor.
If that doesn’t help, run cursor --disable-extensions in your terminal and try a long request.
Check MCP servers: Cursor Settings > Tools & MCP. If you have any servers configured, temporarily disable them. There’s a known issue where MCP timeouts can happen during long operations.
If the issue still happens, please share:
A new console screenshot (Help > Toggle Developer Tools) taken while the error is happening
A new Request ID
Let me know what you find after disabling CodeRabbit.
I understand your concern. This isn’t about “selling” a Cursor review. CodeRabbit, as an AI tool, can actually conflict with Cursor AI during long operations, even when it isn’t active. It’s a technical conflict between extension host processes. If it turns out to be the cause, we’ll fix it. I’m not asking you to stop using CodeRabbit completely.
This is a standard diagnostic step. We temporarily disable the extension to identify the source of the issue. If CodeRabbit isn’t the cause, we’ll keep looking.
After testing with extensions disabled, we’ll be able to pinpoint the exact cause and find a solution without needing to drop CodeRabbit, if it isn’t at fault.
@deanrie It has happened again while CodeRabbit was disabled: Request ID: d7f69b1a-eea4-4501-910e-018db5c4428b
I asked CodeRabbit about what their extension does while it is not active and their response was:
”The CodeRabbit extension does very little while not actively reviewing - it is just listening for editor events and occasionally syncing settings/auth.”
Thanks for the extra info. I can see the screenshot with the serialization error, “invalid int 32: 4294967295”.
This is a known protobuf serialization issue that happens when the Agent runs terminal commands that return values outside the int32 range. It happens especially often with PowerShell commands.
Please try these steps:
Check the terminal commands:
Open Terminal in Cursor when the error happens
See which commands the Agent is running
If you see PowerShell commands with | Select-Object -First N, that might be causing the issue
Workaround:
Add this to .cursorrules: “Never use PowerShell pipelines with Select-Object -First or head for command output truncation”
Use shorter requests to the Agent
I’ll pass this to the engineers. The previous fixes clearly didn’t fully solve the issue.
