Debug Mode NDJSON Ingest

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

In debug mode I keep having this issue

NDJSON Ingest: Cannot start server - port 7768 became unavailable. Please try again.

Port is already in use

Please check the NDJSON port setting and ensure:

The port is not already in use by another service

You have permission to use the port (try a port above 1024)

Operating System
MacOS Tahoe 26.1

I checked, the port is not being used and I tried to restart the system twice, it doesn’t help.

Steps to Reproduce

Debug mode and try to launch a request, follow up message in this case. I closed my laptop and when I came back to continue the fix it displayed this message.

Expected Behavior

Debug mode running as expected

Operating System

MacOS

Version Information

Version: 2.6.14
VSCode Version: 1.105.1

For AI issues: which model did you use?

GPT-5.3 Codex High

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

4

Hey, thanks for the report. This is a known issue in debug mode. The NDJSON ingest server sometimes doesn’t release the port properly, especially after sleep and wake cycles on macOS.

As a workaround, run this in Terminal before using debug mode again:

lsof -ti :7768 | xargs kill -9

This kills any stale process still holding the port. If nothing shows up, meaning the port looks free, try restarting Cursor fully. Use CMD+Q to quit, not just close the window.

If it still happens, try changing the NDJSON port in settings. Search for “NDJSON” in Cursor Settings and set it to a different value like 7769.

The team is aware of the issue. Your report helps us prioritize it. Let me know if the workaround helps.

5

Hello, the workaround worked, thank you for your help on this
Best

1 Like