macOS upgrading to the latest version unresponsive when writing code

Support Bug Reports
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Where does the bug appear (feature/product)?

Cursor for iOS

Describe the Bug

My computer is running macOS, with system version 26.5.2 (25F84), Apple M3 chip, and 16GB of memory. After upgrading to the latest version of cursor recently, I encountered a situation where the IDE and Agent mode were unresponsive when writing code. It kept prompting “planning next moves”. I uninstalled and reinstalled (cleaned the installation directory and restarted the computer), then downloaded the latest installation package for installation. After that, I opened the cursor app, logged in, and found that even simple interface operation buttons were very slow to respond. I tried multiple times but it was ineffective. Finally, I chose to reinstall an earlier version, Version: 3.10.20, and it worked normally.
I’m not sure if others have encountered the same problem

Steps to Reproduce

My computer is running macOS, with system version 26.5.2 (25F84), Apple M3 chip, and 16GB of memory. After upgrading to the latest version of cursor recently

Expected Behavior

I encountered a situation where the IDE and Agent mode were unresponsive when writing code. It kept prompting “planning next moves”.

Operating System

MacOS

Version Information

macOS,with system version 26.5.2 (25F84)
cursor version lastest 3.13

For AI issues: which model did you use?

auto
GPT 5.6 and GPT 5.5

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Hey, thanks for the detailed report. Sounds like you hit a known memory regression in early 3.13 builds. Under high memory pressure, the renderer would lag, which made the whole UI feel sluggish, and the agent could get stuck on “Planning next moves”. The fixes are already shipped, first in 3.13.13, then an extra fix in 3.13.21. The current 3.13.25 includes them.

A couple things:

  • Which exact 3.13.x was slow for you? Most likely 3.13.10, it was the worst.
  • A clean reinstall won’t help because it wipes the app bundle, but not the user state in ~/Library/Application Support/Cursor. That state, accumulated chats and composers, was the main driver of the issue, so it survived reinstalls.

I’d recommend updating to the latest 3.13.25 and doing a normal session. If it slows down again, open Activity Monitor, check memory for the “Cursor Helper (Renderer)” process and the overall memory pressure, then share the numbers here.

If a specific turn gets stuck on “Planning next moves”, Reload Window can help Cmd+Shift+P > Reload Window, or start a new chat and pull context via @Past Chats.

Let me know how it goes on 3.13.25.