For AI issues: which model did you use?
Model name (e.g., Sonnet 4, Tab…)
For AI issues: add Request ID with privacy disabled
Request ID: f9a7046a-279b-47e5-ab48-6e8dc12daba1
For Background Agent issues, also post the ID: bc-…
Additional Information
Add any other context about the problem here.
Does this stop you from using Cursor?
Yes - Cursor is unusable
Sometimes - I can sometimes use Cursor
No - Cursor works, but with this issue
The more details you provide, the easier it is for us to reproduce and fix the issue. Thanks!
Where does the bug appear (feature/product)?
Cloud Agents & Automations (cursor.com/agents) — also occurs in regular Editor Chat/Agent
Describe the Bug
I get “An unexpected error occurred” every time I try to send a message in Agent chat. This happens consistently — in a long existing conversation, in a Forked copy of it, and even in a brand new empty chat with no prior history. The error appears immediately after sending, even for very short test messages.
Steps to Reproduce
Open Cursor and start (or continue) an Agent chat session
Type any message (with or without file/image attachments)
Click send
Error “An unexpected error occurred” appears immediately, sometimes preceded by “Reconnecting…”
Clicking “Try again” produces the same error with a new Request ID
Creating a brand new chat and repeating steps 2-4 still fails
Expected Behavior
The message should be sent and the Agent should respond normally, as it did before this issue started.
For AI issues: add Request ID with privacy disabled
Request ID: 4095894e-ba98-4291-8782-af284e2a7387
Request ID: 189e14e1-4a6c-4ff2-b9db-559dfbbca8d8
Request ID: 4f560775-f81d-4c79-b6a0-7a6452e91749
Request ID: 7f06a203-6255-4f60-9c0f-9873b8f888db
Additional Information
Checked status.cursor.com — showed “All Systems Operational” today (Aug 6). However, there were resolved incidents affecting “Cloud Agents & Automations” and “Anthropic models” the day before (Aug 5). This issue may be a lingering effect from that. I also tried Forking the conversation (thinking it was a context-length issue at 91%/232K tokens), but the fresh New Chat still failed the exact same way, which rules out context length as the cause.
Does this stop you from using Cursor?
Yes - Cursor is unusable
Hey, thanks for the detailed report with the Request ID, that helps a lot. From what I can see, the requests are failing before they ever reach our servers, so this looks like something on the client side or somewhere on the network path. The fact that even a brand-new empty chat fails instantly supports that, it is not related to context length.
A couple things to try right now:
Open App Settings Ctrl+Shift+,, find HTTP/2, and enable Disable HTTP/2. On corporate networks, VPNs, or proxies in Japan, this is a common cause where chat traffic gets blocked but everything else still works.
If you are using a VPN, proxy, or corporate network, try temporarily without them.
To dig deeper, can you share:
Does the error show up instantly under 1 second or after a short pause?
The output from Cursor Settings > Network > Run Diagnostics.
Open Help > Toggle Developer Tools > Console tab, send a message, and see if any red errors appear, especially a line like No resource accessor found for composer. Please send a screenshot.
Which email is the Cursor app logged into the account icon in the bottom left? I want to make sure we are looking at the right account.
If you see No resource accessor found for composer in the Console, there is a proven workaround. Close Cursor and launch it with a clean profile using the --user-data-dir flag, pointing it to a new empty folder, then open the real project. Let me know how it goes.
