Hey, this is a known class of bugs with extension host timeout on Windows. We’re tracking the issue, but I can’t share an ETA for a fix yet.
I can see you’ve already tried a lot. One workaround that recently helped in a similar thread Failed to start new Agent chat was that the workspace was untrusted, and in the new layout the trust-folder dialog didn’t show up, silently blocking agent execution.
- Fully close Cursor.
- Open the project via
cursor --classic <path-to-project>. - In classic mode you should see the “Do you trust the authors of this folder?” dialog. Click Trust.
- Close Cursor and open it again normally.
This matches a known bug where the Glass layout hides the trust prompt. Since the request IDs aren’t reaching the backend, and network diagnostics pass, the root cause is on the client side, and the trust-folder state is the most common trigger.
If this doesn’t help, please share:
- Output from Help > Toggle Developer Tools > Console at the moment the agent hangs, look for extension host / cursor-socket errors
- Whether it reproduces in an empty folder
mkdir test && cursor test, then submit a simple prompt - Whether there are fresh
exthost.logfiles with errors in%APPDATA%\Cursor\logs\
Separately, the 2 to 3 hour echo loops are model behavior, not extension host behavior. If you can share a link to a specific chat where the model got stuck, I’ll pass it to the team.