When working with multiple Cursor windows open, especially when the agent is running in one of them, the application frequently freezes, causing all windows to go black or white.
Sometimes a system dialog appears with the message:
“This window is not responding. Do you want to close it?”
The issue severely disrupts workflow and often happens mid-typing, resulting in lost time and productivity.
Steps to Reproduce
Open two different projects in Cursor (separate windows).
Begin working in both — e.g., typing in one, running the agent in another.
After a short time, all windows freeze.
One or more windows turn black or white.
Expected Behavior
Cursor should be stable and responsive when multiple windows or projects are open simultaneously.
Running the agent in one window should not impact the stability of other open instances.
Operating System
Windows 10/11
Current Cursor Version (Menu → About Cursor → Copy)
Now it’s gotten much worse.
It freezes every few seconds — whether an agent is running or not, whether I have one window open or several.
It freezes while I’m typing, while an agent is working, sometimes the screen just turns black for a few seconds and then comes back — like there’s some terrible background process interrupting everything.
I honestly wish this would stop.
It’s causing me serious damage — the amount of time I now waste just trying to enter a single command into Cursor without it freezing has become a disaster.
First of all, I’m happy for you.
Are you in the same version as me?
Are you working on at least two projects at the same time?
Do you have long chats?
What models do you work with?
Hey, thanks for the report. Is this happening in both windows or in a specific window with a specific project? Could you please check by creating two completely new projects, open them, and see if the issue persists?
So here’s what I tested
two interesting findings that might help identify what’s causing the issue:
If I close all instances of Cursor and reopen it, things work fine for a few agent interactions but then the freezing starts again.
It clearly only happens in projects with a large codebase.
In a new or empty project, or one with just a couple of files, there’s no freezing at all.
But the whole point of using Cursor is to work with large codebases — that’s exactly what I need it for.
same issue for me as well since last update it uses lot of cpu and memory comsumption due to latest update leading to crashing of system black screen and cursor crashes
Im using 1.3.9 after being away from my project for a week now. I can’t get command to take < 2 minutes to respond. I ask it to check a field in the database. It runs “docker ps” first to check everything is up. Fine, very basic, but no response to a “docker ps” after 2 minutes.
I run “docker ps” , 1 second. I used to use “move to background” when the terminal integration failed but no longer have that option. I’ve stopped using it out of frustration today. will try again in a few days.
The issue happens in all projects!
It’s still not fixed — even in the latest version.
It’s frustrating and wastes a lot of my time!
But…
The problem doesn’t appear in a project that has almost no files.
But honestly — what project these days has only a few files?
When a single project with many files is open, it freezes all windows,
and I’ve already asked you several times:
There’s no logical reason for the processes to be so tightly coupled!
It looks like you’re running out of RAM and the OS starts using the swap file extensively, and that’s why all windows freeze etc. etc. I have a similar issue in my project with very large SDK. In my case it’s Intellisense trying to index all files in the SDK, used or not, and consuming ~50 GB in the process.
Weird input buffering is occurring after several UI events of certain kinds. The attached .gif shows this in the menus.
It also happens with mouse-wheel scrolling in the code editor, but this is harder to demonstrate in a screen cap. I scroll down 3 notches, the editor moves down only 2. I scroll up three notches, the editor moves down 1, then up two. The third down has only been applied when I scroll up once. In other words, every movement is one step behind.
Occasionally, when something falls behind, it causes the entire UI to become pitch black for a moment, and nothing is visible.
Steps to Reproduce
Move the mouse back and forth over the menus. Scroll back and forth in the editor.
Expected Behavior
Mouse pointer and scroll wheel movements take effect immediately. There is no input buffering.
Screenshots / Screen Recordings
Operating System
Linux
Current Cursor Version (Menu → About Cursor → Copy)
This has been happening for a while on my system, but I thought the lag issue that’s blowing up might be related somehow, so reporting it now. Notably, VS Code doesn’t suffer from this issue. My workstation has plenty of memory, storage, and compute.
