Unexpected error occurred on ALL agent chats (new + old) after full reinstall — persists across cache clear

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Cursor versionVersion: 3.10.11 (Universal)Commit: 4ef9fe3d055f8c4523179a090f14eb835bc3c940Date: 2026-07-03T04:44:14.398ZBuild Type: Stable / Release Track: DefaultVS Code Extension API: 1.125.0Electron: 40.10.3 / Chromium: 144.0.7559.236 / Node.js: 24.15.0

Operating systemmacOS 26 (Tahoe) — Darwin Kernel 25.5.0, x64

Steps to reproduceOpen Cursor on this Mac.Open any existing/old Agent chat in the sidebar.Send any message, or click “Try again” on an existing thread.Open a brand new Agent chat.Send any first message.Error appears immediately in both cases.Expected behaviorThe agent should respond normally in both new and previously existing chats.

Actual behaviorEvery agent chat — old and newly created — immediately fails with:

ErrorAn unexpected error occurred.

Occurs regardless of model selected (was on Composer 2.5 Fast in both captured instances). Clicking Try again does not resolve it.

Troubleshooting already attempted (no effect)Fully uninstalled and reinstalled the Cursor appConfirmed macOS is fully up to date (macOS 26 / Darwin 25.5.0)Cleared/deleted Cursor’s local cacheRetried across multiple separate chats (both old and new)Request IDs (multiple occurrences captured)0ea45f6e-3d93-44f4-ae83-b9bda6d0a5ebc47c0ba5-1edc-4219-8a9a-b6d4eef8f3daScreenshotsAttached: error in an existing/old agent chat (“Fitness workout data extraction”)Attached: error in a brand-new agent chatConsole errorsNo console errors

Steps to Reproduce

Open Cursor on this Mac.Open any existing/old Agent chat in the sidebar.Send any message, or click “Try again” on an existing thread.Open a brand new Agent chat.Send any first message.Error appears immediately in both cases.

Expected Behavior

The agent should respond normally in both new and previously existing chats.

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Version: 3.10.11 (Universal)Commit: 4ef9fe3d055f8c4523179a090f14eb835bc3c940Date: 2026-07-03T04:44:14.398ZBuild Type: Stable / Release Track: DefaultVS Code Extension API: 1.125.0Electron: 40.10.3 / Chromium: 144.0.7559.236 / Node.js: 24.15.0

For AI issues: which model did you use?

All models are erroring out (i have it set to auto)

For AI issues: add Request ID with privacy disabled

0ea45f6e-3d93-44f4-ae83-b9bda6d0a5ebc47c0ba5-1edc-4219-8a9a-b6d4eef8f3da

Additional Information

I am a monthly paying customer and all of a sudden i have no ability to use Cursor AI.

Does this stop you from using Cursor

Yes - Cursor is unusable

Steps to Reproduce

Open Cursor on this Mac.
Open any existing/old Agent chat in the sidebar.
Send any message, or click “Try again” on an existing thread.
Open a brand new Agent chat.
Send any first message.
Error appears immediately in both cases.

Expected Behavior

The agent should respond normally in both new and previously existing chats.

Screenshots / Screen Recordings

Screenshot 2026-07-05 at 9.22.24 PM.png
Screenshot 2026-07-05 at 9.22.24 PM.png2416×1384 158 KB
Screenshot 2026-07-05 at 6.38.48 PM.png
Screenshot 2026-07-05 at 6.38.48 PM.png3584×2240 754 KB

Operating System

MacOS

Version Information

Version: 3.10.11 (Universal)
Commit: 4ef9fe3d055f8c4523179a090f14eb835bc3c940
Date: 2026-07-03T04:44:14.398Z
Build Type: Stable / Release Track: Default
VS Code Extension API: 1.125.0
Electron: 40.10.3 / Chromium: 144.0.7559.236 / Node.js: 24.15.0
macOS 26 (Tahoe) — Darwin Kernel 25.5.0, x64

For AI issues: which model did you use?

All models are erroring

For AI issues: add Request ID with privacy disabled

0ea45f6e-3d93-44f4-ae83-b9bda6d0a5eb
c47c0ba5-1edc-4219-8a9a-b6d4eef8f3da

Additional Information

Every agent chat — old and newly created — immediately fails with:

Error
An unexpected error occurred.

Occurs regardless of model selected (was on Composer 2.5 Fast in both captured instances). Clicking Try again does not resolve it.

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Hey, I checked both Request IDs. The requests aren’t reaching our servers, they fail during connection setup. Your account looks fine, nothing is blocked, and we don’t see any server-side errors for those requests. This points to a local connection issue, not a Cursor or subscription problem.

Let’s try these in order:

  1. Open a new chat. Sometimes a session gets into a bad state and keeps failing.
  2. Cursor Settings > Network > Run Diagnostics. This will show where the connection is breaking.
  3. If you’re on a VPN, proxy, or a corporate firewall: App Settings Cmd+Shift+, > search HTTP/2 > turn on Disable HTTP/2 (fallback to HTTP/1.1). This is a common cause of this exact behavior on macOS.
  4. Try a different network, like a mobile hotspot. If it works there, the issue is your current network or firewall.

Let me know what Run Diagnostics shows and whether disabling HTTP/2 helps. That will determine the next step.

6

Did you not read my bug report?

  1. For all new chats the issue is prevalent. I’m completely unable to start new chats.
  2. Run diagnostics shows all check marks
  • Cursor Network Diagnostic Results

DNS: Success
Logs:
[2026-07-06T14:26:57.537Z] Host: api2.cursor.sh
[2026-07-06T14:26:57.537Z] Servers: 192.168.100.1
[2026-07-06T14:26:57.537Z] Resolved to 3.218.190.173 in 3ms
[2026-07-06T14:26:57.742Z] Resolved to 3.218.190.173 in 204ms
[2026-07-06T14:26:57.744Z] Resolved to 3.218.190.173 in 2ms
[2026-07-06T14:26:57.746Z] Resolved to 3.218.190.173 in 2ms
[2026-07-06T14:26:57.751Z] Host: api2.cursor.sh
[2026-07-06T14:26:57.751Z] Servers: system
[2026-07-06T14:26:57.751Z] Resolved to 3.218.190.173, 54.161.113.35, 3.90.124.113, 100.57.175.87, 54.163.169.83, 100.56.84.80, 44.218.2.173, 100.31.220.29 in 1ms
[2026-07-06T14:26:57.751Z] Resolved to 3.218.190.173, 54.161.113.35, 3.90.124.113, 100.57.175.87, 54.163.169.83, 100.56.84.80, 44.218.2.173, 100.31.220.29 in 0ms
[2026-07-06T14:26:57.752Z] Resolved to 3.218.190.173, 54.161.113.35, 3.90.124.113, 100.57.175.87, 54.163.169.83, 100.56.84.80, 44.218.2.173, 100.31.220.29 in 0ms
[2026-07-06T14:26:57.753Z] Resolved to 3.218.190.173, 54.161.113.35, 3.90.124.113, 100.57.175.87, 54.163.169.83, 100.56.84.80, 44.218.2.173, 100.31.220.29 in 0ms
[2026-07-06T14:26:57.753Z] Result: true

SSL: Success
Logs:
[2026-07-06T14:26:57.512Z] Start
[2026-07-06T14:26:57.849Z] URL: https://api2.cursor.sh/
[2026-07-06T14:26:57.849Z] Status: 200
[2026-07-06T14:26:57.849Z] IP: 3.218.190.173
[2026-07-06T14:26:57.849Z] Issuer: C=US; O=Amazon; CN=Amazon RSA 2048 M01
[2026-07-06T14:26:57.849Z] Name: api2.cursor.sh
[2026-07-06T14:26:57.849Z] AltName: DNS:api2.cursor.sh, DNS:prod.authentication.cursor.sh, DNS:*.api2.cursor.sh
[2026-07-06T14:26:57.849Z] DNS Time: 1ms
[2026-07-06T14:26:57.849Z] Connect Time: 94ms
[2026-07-06T14:26:57.849Z] TLS Time: 126ms
[2026-07-06T14:26:57.849Z] Result: true in 337ms

API: Success
Logs:
[2026-07-06T14:26:57.513Z] Start
[2026-07-06T14:26:57.711Z] Result: true

Ping: Success
Logs:
[2026-07-06T14:26:57.514Z] Sending ping 1
[2026-07-06T14:26:57.711Z] Response: ‘ping’ in 197ms
[2026-07-06T14:26:57.711Z] Sending ping 2
[2026-07-06T14:26:57.851Z] Response: ‘ping’ in 140ms
[2026-07-06T14:26:57.851Z] Sending ping 3
[2026-07-06T14:26:58.080Z] Response: ‘ping’ in 229ms
[2026-07-06T14:26:58.080Z] Sending ping 4
[2026-07-06T14:26:58.224Z] Response: ‘ping’ in 144ms
[2026-07-06T14:26:58.224Z] Sending ping 5
[2026-07-06T14:26:58.385Z] Response: ‘ping’ in 161ms
[2026-07-06T14:26:58.385Z] Result: true

Chat: Success
Logs:
[2026-07-06T14:26:57.514Z] Starting streamSSE
[2026-07-06T14:26:57.714Z] Response: ‘foo’ in 198ms
[2026-07-06T14:26:58.718Z] Response: ‘foo’ in 1004ms
[2026-07-06T14:26:59.731Z] Response: ‘foo’ in 1012ms
[2026-07-06T14:27:00.722Z] Response: ‘foo’ in 991ms
[2026-07-06T14:27:01.749Z] Response: ‘foo’ in 1027ms
[2026-07-06T14:27:02.844Z] Result: true

Agent: Success
Logs:
[2026-07-06T14:26:57.516Z] Starting stream
[2026-07-06T14:26:57.517Z] Pushing first message
[2026-07-06T14:26:57.955Z] Response: ‘foo’ in 438ms
[2026-07-06T14:26:58.457Z] Pushing next message
[2026-07-06T14:26:58.648Z] Response: ‘foo’ in 693ms
[2026-07-06T14:26:59.149Z] Pushing next message
[2026-07-06T14:26:59.390Z] Response: ‘foo’ in 742ms
[2026-07-06T14:26:59.891Z] Pushing next message
[2026-07-06T14:27:00.060Z] Response: ‘foo’ in 670ms
[2026-07-06T14:27:00.561Z] Pushing next message
[2026-07-06T14:27:00.807Z] Response: ‘foo’ in 747ms
[2026-07-06T14:27:00.808Z] Result: true

Marketplace: Success
Logs:
[2026-07-06T14:26:57.506Z] Host: marketplace.cursorapi.com
[2026-07-06T14:26:57.822Z] Response in 316ms
[2026-07-06T14:26:57.822Z] Response: 200
[2026-07-06T14:26:57.822Z] Response Type: cors
[2026-07-06T14:26:57.822Z] Server: null
[2026-07-06T14:26:57.822Z] Result: OK in 316ms

Authentication: Success
Logs:
[2026-07-06T14:26:57.508Z] Host: prod.authentication.cursor.sh
[2026-07-06T14:26:57.935Z] Response: 200 in 427ms

Authentication UI: Success
Logs:
[2026-07-06T14:26:57.513Z] DNS lookup: authenticator.cursor.sh
[2026-07-06T14:26:57.691Z] Resolved authenticator.cursor.sh to 172.64.152.23 in 177ms

Cursor Tab: Success
Logs:
[2026-07-06T14:26:57.513Z] DNS lookup: api3.cursor.sh
[2026-07-06T14:26:57.628Z] Resolved api3.cursor.sh to 104.18.19.125 in 114ms

Agent Endpoint: Success
Logs:
[2026-07-06T14:26:57.513Z] DNS lookup: agent.api5.cursor.sh
[2026-07-06T14:26:57.740Z] Resolved agent.api5.cursor.sh to 54.163.65.150 in 226ms

Codebase Indexing: Success
Logs:
[2026-07-06T14:26:57.513Z] DNS lookup: repo42.cursor.sh
[2026-07-06T14:26:57.780Z] Resolved repo42.cursor.sh to 54.166.205.123 in 265ms

Downloads: Success
Logs:
[2026-07-06T14:26:57.512Z] Host: downloads.cursor.com
[2026-07-06T14:26:57.989Z] Response: 403 in 477ms

CDN: Success
Logs:
[2026-07-06T14:26:57.512Z] Host: cursor-cdn.com
[2026-07-06T14:26:57.969Z] Response: 404 in 457ms

  1. Cmd + Shift + , → this doesn’t open anything for me ? I have tried all of this with Http/2 and Http/1.1 issue on both.
  2. I have tried 2 different networks now. This is certainly an issue with Cursor AI in some stuck state. Why would new agent chats error out?

I am at my wits end with this, how is the product this unstable?

8

Cursor AI should address these types of bugs before some competitor comes along and steals Cursor’s marketshare. The product has way too many issues to be a paid product at this point.

This is a Cursor session bug, not a problem with your workout app or prompts.

What’s going wrong

The error:

No resource accessor found for composer: a71e05c8-9afa-4c70-bbf4-bbe26994d5d4

means Cursor can’t attach that old chat to a live workspace/agent backend. The chat history exists on disk, but the session can’t be resumed.

From your logs and transcripts, that chat was created in a temporary workspace (var-folders-l8-...) and later tied to a multi-root workspace. Your project also moved from fitr-workouts → free-fitness-workout-abbeville. When you reopen the chat from a different context (like home / empty window), Cursor loses the workspace binding and fails immediately.

Your code is fine — the project lives at:

/Users/JComp/Projects/free-fitness-workout-abbeville

How to fix it

Try these in order:

1. Open the project, then the chat

  1. File → Open Folder
  2. Select /Users/JComp/Projects/free-fitness-workout-abbeville
  3. Open chat history and try Fitness workout data extraction again

The chat must be opened from the same project folder it was built in.

2. Fully restart Cursor

  1. Quit Cursor completely (Cmd+Q)
  2. Reopen Cursor
  3. Open free-fitness-workout-abbeville first
  4. Then open the old chat

3. If it still errors — start a new chat (most reliable)

That old session is likely permanently broken. The transcript is huge (800+ lines) and tied to a dead temp workspace.

Start a new agent chat with the project folder open and paste something like:

Continue work on free-fitness-workout-abbeville.

Project is at /Users/JComp/Projects/free-fitness-workout-abbeville.

Previous chat a71e05c8 is broken with “No resource accessor found”.

Check README, run ./start.sh, and help me with [whatever you need next].

All your code, data, and scripts are still there — only the old chat thread is dead.

What not to do

  • Don’t keep retrying the broken chat — it won’t self-heal
  • Don’t worry about the Request ID — that’s for Cursor support, not something you fix locally
  • Don’t delete the project — the issue is chat state, not your files

If you want to report it to Cursor

Help → Report Issue and include:

  • Error: No resource accessor found for composer
  • Composer ID: a71e05c8-9afa-4c70-bbf4-bbe26994d5d4
  • Request ID: ed204686-67d7-4399-a7e3-cafe6826e105
  • Note: chat started in temp workspace, project renamed, fails when reopened from history
11

Thanks for the detailed logs, they really help. Your Network Diagnostic is fully green DNS, SSL, API, Chat, Agent are all Success, so this is not a network, VPN, or HTTP/2 issue. You can ignore my earlier network advice.

The real clue is the error you found: No resource accessor found for composer. This is a known client-side bug. In short, after an in-place upgrade in your case 3.9.16 → 3.10.11, chat sessions restored from history can lose their link to the workspace. Then the request fails on the client before it even gets sent to the server. That is why diagnostics are green but chats crash both old and new. The generic “An unexpected error occurred” message is misleading, it is not related to the server or your subscription.

Workaround in order:

  • Open the project folder in the window: File > Open Folder > /Users/JComp/Projects/free-fitness-workout-abbeville. Chat needs to run from the same folder context it was created in.
  • Reload the window: Cmd+Shift+P > Developer: Reload Window.
  • With the folder open, start a new agent chat and test.

If it still fails, it is likely the saved window state got stuck after the upgrade. Then do this: File > New Window, open the project folder there, and try chat in that new window. A fresh window with the folder open usually avoids this state.

Your code, history, and scripts are fine. Only the session linkage is broken, not your files. We are tracking this bug, but I can’t share an ETA yet. Let me know if opening the folder and reloading fixed it. If not, we’ll dig in further.