Cursor Agent on macOS 27 stuck in "Exploring" (Read/Grep never return): `The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.`

Context

Source(s): https://forum.cursor.com/t/cursor-agent-gets-stuck-while-exploring-files-and-never-generates-a-code-change-on-macos-27/171885 Signal: 512 views, 17 posts; staff said they had similar reports from other macOS 27 users; three users explicitly confirmed one of the fixes below. Status: reported working by source, not reproduced by us (workaround only; root fix not confirmed).

Problem

After upgrading to macOS 27 on Apple Silicon, the Cursor agent understands the request and starts reading and grepping files, but never moves on to making changes; it stays in "Exploring" until stopped, or the Agents Window gives up after about 70 seconds with the error above. It happens even in a fresh, empty folder.

Error (redacted / normalized)

The agent execution provider did not respond in time. This may indicate the extension host is not running or is unresponsive.

[anysphere.cursor-retrieval] spawn Unknown system error -86

Applies when

macOS 27.0 on Apple Silicon, Cursor 3.20.21 and 3.21.13.

Confirm it is this problem

1. A trivial agent request in a new empty folder ("Search this folder for the word hello") also hangs or times out (staff's test). → expect: it hangs, so the project is not the cause.
2. Optional: Help > Toggle Developer Tools > Console shows spawn Unknown system error -86 (one commenter). Our inference: error -86 is macOS's "bad CPU type in executable", meaning an x86-only helper binary cannot run.

Not this when / boundary

The Terminal warnings RequestStore#acceptReply was called without receiving a matching request and MaxListenersExceededWarning alone; staff said they are harmless noise when more than one Cursor window is open. Intel Macs or macOS versions before 27 (our inference).

Root cause

Staff said the local Read and Grep steps stopped returning results after the macOS 27 upgrade, so the agent never gets its tool results. Staff later pointed to an x86-64-only git binary as one trigger. A commenter's explanation that macOS 27 no longer restores Rosetta 2 after an upgrade came from an AI assistant and was not confirmed by staff. Root cause not confirmed.

Fix

1. Install Rosetta 2 with softwareupdate --install-rosetta --agree-to-license, then quit Cursor completely (Cmd+Q) and reopen it. → expect: the original poster ("That helped") and another commenter ("helped") confirmed the agent works again; the commenter who posted the Rosetta command also said "this worked for me".
2. Staff alternative: check whether your git binary is x86-64 only, and install an arm64-compatible git instead; staff said this should also fix it without Rosetta (not confirmed by a user in this thread).
3. If Rosetta is installed and it still hangs: open Cursor Settings, turn on "Index Repositories for Instant Grep", and restart Cursor (suggested by staff). → expect: a commenter for whom Rosetta did not help confirmed that turning it back on made it work again; the next reply ("YES, i have been battling this for two days! Finally.") reads as a second confirmation (our inference).

How to verify

The "Search this folder for the word hello" request finishes within a few seconds, and a real request gets past "Exploring" and applies changes.

What did not work

Fully quitting and reopening Cursor, launching Cursor from Terminal, the GC Agent KV Blobs command, Developer: Reload Window, and checking Files and Folders / Local Network permissions (original poster and a commenter). For the commenter in step 3, reinstalling Rosetta, removing an old x86 git, and forcing git.path did not help.

Verified scope

macOS 27.0 on Apple Silicon, Cursor 3.20–3.21, September 2026.

Becomes obsolete when

A Cursor release handles missing Rosetta / x86-only helpers on macOS 27 without hanging.