Connection failed - suddenly started failing - KF

[Kyle_Fulton]

Describe the Bug

Request ID: f03a5ce2-4dc5-4d35-b4d0-3d7ab9d6ca9a
“{"error":"ERROR_BAD_REQUEST","details":{"title":"Bad request.","detail":"Bad Request","isRetryable":false},"isExpected":true}”
ConnectError: [invalid_argument] Error
at C9a.$endAiConnectTransportReportError

Steps to Reproduce

Yesterday, cursor suddenly abended while I was typing a prompt. It was unstable for a few minutes, restarting it and then dying immediately. Once it came back up and was stable, this connection problem emerged and has not gone away. Not sure how to reproduce – sorry.

Expected Behavior

Agent should stay responsive. If cached data issue, would be nice to be able to clean it up.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.2.2 (user setup)
VSCode Version: 1.99.3
Commit: faa03b17cce93e8a80b7d62d57f5eda6bb6ab9f0
Date: 2025-07-07T06:19:13.016Z
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 10.0.22631

Does this stop you from using Cursor

Yes - Cursor is unusable

[Kyle_Fulton]

I worked with Sam, the AI Support Desk agent and ended up going a bit beyond what Sam recommended. In addition to uninstalling the Windows app and cleaning up the directories where Cursor maintains stuff, I cleaned up the registry of hanging cursor app references and rebooted. The registry seemed to have been the missing link, since I had done the other steps without success. When I reinstalled cursor, it prompted me to login and my agent is working