When Cursor stops working, the cause is usually one of a handful of documented problems: a network or proxy that blocks HTTP/2, a usage allowance that has run out, an outdated build, or an extension that conflicts with Cursor's AI. The quickest first check is Cursor Settings > Network > Run Diagnostics, which tests your connection to Cursor's servers.
This guide collects the fixes from Cursor's own troubleshooting help pages, read on 26 October 2026, grouped by symptom. It covers Cursor the AI code editor, not a mouse pointer that stopped moving.
What should you try first?
Work down this list before digging into a specific symptom:
- Run network diagnostics. Open Cursor Settings > Network and click Run Diagnostics.
- Update Cursor. Press Cmd/Ctrl + Shift + P, run Cursor: Attempt Update, and restart when prompted.
- Fully restart. Quit Cursor completely (Cmd + Q on Mac, or exit from the tray on Windows and Linux), not just reload the window.
- Check your usage. On current plans, open Usage at grok.com/dashboard; on legacy plans, use the Spending tab in your Cursor dashboard.
- Rule out extensions. Run
cursor --disable-extensionsfrom a terminal and see if the problem goes away.
Why do Cursor's AI features stop working on some networks?
Proxies that block HTTP/2. The network help page explains: "Cursor uses HTTP/2 for streaming responses. Some corporate proxies (like Zscaler) block HTTP/2." The fix is to go to Cursor Settings > Network, set HTTP Compatibility Mode to HTTP/1.1 and restart Cursor.
Firewalls. If outbound connections are blocked, these domains need to be allowed:
*.cursor.sh*.cursor-cdn.com*.cursorapi.com*.cursorvm.comand*.*.cursorvm.com
VPN DNS problems. Cursor "can inherit DNS settings from a previously active VPN." If AI features fail with DNS errors after you disconnect, fully restart Cursor. If that doesn't help, check your system DNS with scutil --dns on macOS or /etc/resolv.conf on Linux.
A "suspicious activity" message. This appears when a request is blocked as a security measure, and VPNs can trigger it. Turn the VPN off first. If it persists, start a new chat, wait a few minutes, or sign in with a different method (Google or GitHub).
Remote SSH. AI requests go from your local machine to Cursor's servers, not from the remote host. Check your local connection, make sure the remote server isn't out of memory or CPU, and consider raising the SSH keep-alive:
Host your-server
ServerAliveInterval 60
ServerAliveCountMax 3
Why did Cursor Tab stop suggesting code?
The Tab troubleshooting page lists four causes:
| Cause | Fix |
|---|---|
| Plan limits: Free and legacy Hobby have a limited Tab allowance | Wait for the reset or upgrade |
| A network that blocks HTTP/2 | Turn on HTTP Compatibility Mode, then restart |
| An outdated version | Run Cursor: Attempt Update |
| No internet | Reconnect; Tab needs a connection |
Also click the Tab status indicator in the bottom-right corner. Tab may be snoozed or disabled globally or for that file type. If suggestions are poor rather than missing, make a few manual edits first, since Tab builds context from your recent edits. The Cursor Tab guide covers its settings in detail.
What if Cursor Agent isn't working properly?
Agent can't see your files. From the Agent troubleshooting page:
- Check
.cursorignorein the project root. Files listed there are blocked from Agent, codebase search and@mentions. See the .cursorignore guide. - Check
.gitignore, which can also hide files. - Reindex: open the command palette and search for "Reindex."
- Attach the file directly by typing
@and its name.
"Agent Execution Timed Out." This means "Cursor's extension host didn't finish starting within 60 seconds." Collect logs before changing anything: run Developer: Export Logs..., select Main, Window and Extension Host, and check Output > Extension Host. Send the zip to support with your OS and Cursor version. On managed machines, antivirus or EDR software is one possible cause, and Cursor has an endpoint security page for IT teams.
Commands behave differently. Cursor sets CI=1 when Agent runs terminal commands. If your tools act differently in CI mode, prefix the command with unset CI && or add a rule telling Agent to do so.
Agent made changes you don't want. Hover over an earlier message and click Restore Checkpoint. Checkpoints are local and separate from git, so keep using git for real version control.
Agent hit a usage limit. When your allowance runs out you'll see a notification in the editor. The usage limits page says that on current plans you can keep working from prepaid credit, wait for the weekly reset or upgrade. On legacy plans, you can turn on on-demand usage or upgrade. The Cursor pricing guide explains the pools.
A model is missing. Some models aren't available in certain regions because of provider restrictions. Cursor suggests using Auto, trying another provider, or adding your own API key. Free and Plus only show Cursor's own models. See Cursor models.
Why won't Cursor let me sign in?
Cursor's sign-in page is moving to accounts.spacex.ai and accounts.x.ai, replacing authenticator.cursor.sh. The sign-in domains page says existing sessions stay signed in. As of 26 October 2026, that page said sign-in falls back to the old page if the new hosts are blocked, and Cursor announced that this temporary fallback would be retired on October 30, 2026, after which sign-in requires accounts.spacex.ai and accounts.x.ai. Check that page for the current status.
If your network uses an allowlist, ask IT to add *.spacex.ai, *.x.ai, *.grok.com, *.grokusercontent.com and *.grokipedia.com, or at least the minimum hosts listed on that page, alongside the Cursor domains above.
What if Cursor won't start or shows a blank screen?
From the installation and startup page:
- Blank screen: quit and restart. On Mac, move Cursor to Trash and reinstall from cursor.com/download. On Windows, run Cursor as administrator.
- "Cursor is damaged" on macOS: Cursor says this "is a macOS issue, not a corrupted download." Quit Cursor, force-quit leftover processes in Activity Monitor, wait a minute and reopen. If it persists, delete and re-download, then restart your Mac.
- Disk filling up: stored Agent chats are usually the biggest cause. Run Delete Old Chats... from the command palette, then GC Agent KV Blobs, which actually shrinks the database file. Old worktrees under
~/.cursor/worktrees/can also add up; limits are under Settings > Worktrees > Cleanup in the Agents Window.
Why is Cursor slow or using a lot of CPU?
The performance page says high usage "typically stems from extensions or settings issues." Two fixes:
- Run
cursor --disable-extensionsto test without extensions, then re-enable them one at a time. - Add large generated folders such as
dist/,build/and.next/to.cursorignore.
Extensions are also the usual suspect when shortcuts or Tab misbehave. Cursor's extension conflicts page notes that "Other AI coding assistants are the most common source of conflicts." Use Disable All Installed Extensions from the command palette, then turn them back on one by one.
What if an MCP server won't connect?
The MCP help page suggests:
- Open the Output panel (Cmd/Ctrl + Shift + U) and select MCP Logs.
- Toggle the server off and on under Customize > MCPs, or remove and re-add it.
- If the server needs environment variables from your shell profile, make sure Cursor can see them, then restart Cursor.
The Cursor MCP guide covers setup and mcp.json.
How do you report a bug to Cursor?
If nothing above works, post on the Cursor forum with the details the bug report page asks for: Cursor version (Cursor > About Cursor), operating system, steps to reproduce, expected and actual behavior, screenshots, console errors (Help > Toggle Developer Tools) and a request ID, which you copy from the ... menu on the chat response.
One detail matters for agent problems: with Privacy Mode on, support can only see which model was used and whether tools failed. For behavior issues, Cursor suggests temporarily enabling Share Data, reproducing the problem, sending the new request ID, then switching back.
Keep your setup in one place
Reinstalling or switching machines is easier when your prompts don't live only in chat history. Kipt keeps prompts and Agent Skills as Markdown in a private GitHub repo you own, so they survive a fresh install or a move to another tool.