Cursor is very slow and keeps becoming unresponsive

Support Bug Reports
7

Hey, I saw the diagnostics screenshot. Chat is crashing with the error “streaming responses are being buffered by a proxy”. This error is misleading. You do not actually have a proxy. The real issue is high latency to our streaming servers. api2.cursor.sh in China and India goes directly to AWS US without a Cloudflare edge, so it can be slow. Your backend is responding fine, and the slowness is client-side buffering.

This is a known issue and we do not have an ETA for a fix yet. A workaround that definitely worked for a user with the same symptom is here: Chat & Agent streaming blocked — proxy buffering error (India, mobile network)

  • Disable HTTP/2: Ctrl+, → search HTTP/2 → turn on Disable HTTP/2 → fully restart Cursor, not just close the window
  • If that does not help, try switching DNS to 1.1.1.1 or 8.8.8.8
  • As a last option, try Cloudflare WARP: https://one.one.one.one/ It is free and routes traffic through Cloudflare edge nodes

Let me know if disabling HTTP/2 helps. For most users, that is enough.