When we open the cursor it crashes the application

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Whenever we open the Cursor it gets crashed and IDE is not opening.
When we click on Cursor Icon It just flashes the screen for opening and it vanishes.

Steps to Reproduce

Click Start
Click Cursor icon
Verify weather Cursor is opened

Screenshots / Screen Recordings

Operating System

Windows 10/11

Version Information

Version: 3.20.21 (user setup)
VS Code Extension API: 1.128.0
Commit: f09fca384ceca23f7bf21f9c23655b162641d740
Date: 2026-09-13T19:02:51.781Z
Layout: IDE
Build Type: Stable
Release Track: Default
Electron: 42.10.0
Chromium: 148.0.7778.280
Node.js: 24.18.1
V8: 14.8.178.38-electron.0
xterm.js: 6.1.0-beta.291
OS: Windows_NT x64 10.0.26100

Does this stop you from using Cursor

Yes - Cursor is unusable

5

Hey @Ketan_Pardeshi, thanks for the report and the recording.

One thing stands out on our side: after each launch, Cursor 3.20.21 on your PC actually keeps running in the background for several minutes and talks to our servers normally. So it looks like the window is being hidden or placed where you can’t see it, rather than the app crashing. Could you try the following and tell us what you see at each step?

  1. Click the Cursor icon in the Start menu once, and wait about 10 seconds.
  2. Hold Alt and press Tab. Is there a Cursor window in the switcher? If yes, select it. If it still doesn’t appear on screen, keep it selected and press Win + Shift + Left Arrow, then Win + Up Arrow.
  3. Look at the bottom-right corner of the taskbar, next to the clock. Click the small ^ arrow. If there is a Cursor icon there, single-click it (it shows or hides the Cursor window).
  4. Open Task Manager, go to the Details tab, and look for Cursor.exe entries. Are any listed? Please tell us yes or no.
  5. If they are listed, select each Cursor.exe and click End task, then launch Cursor again.
  6. If you use an external monitor or a docking station, check whether the window opened on the other screen, or whether a monitor is connected but switched off.

If none of that helps, please attach %APPDATA%\Cursor\logs\<newest folder>\main.log from a fresh launch attempt. Thanks!

7

I’ve been having the same issue the past couple of days. There are no hidden Cursor windows, I don’t have the taskbar icon enabled, and there are no Cursor.exe processes running when the app is closed. I’ve attached the most recent main.log from my machine.

main.log (601 Bytes)

8

I checked using Alt+Tab It is not there.
I also checked the Task Manager for ppened Apps it doesn’t show Cursor in processes.
I use multiple windows, I saw all the windows, it is not there.
Definately It is not working from start menu or directly clicking on cursor

Workaround: Start > Cursor > Right Click >Select Project. It opens the Cursor.

main.log (702 Bytes)

12

Hey @Ketan_Pardeshi and @tbowersoxbt, thanks for the logs, that was exactly what we needed!

@Ketan_Pardeshi your log shows Windows refusing to start Cursor’s protected window process (the log line is "renderer process gone, reason: launch-failed, code: 21"). That code means the operating system blocked the security sandbox Cursor uses for its window, which is almost always caused by security or application-isolation software on the PC rather than by Cursor itself. The fact that opening a project from the right-click menu works while the Start menu icon does not also points that way. From your recording it looks like this laptop runs HP Wolf Security / HP Sure Click, which does exactly this kind of interception.

@tbowersoxbt, your log stops before the point where that line would appear, so I cannot yet tell if it is the same cause on your side, but the symptoms match.

Could you both try the following and tell us what happens at each step?

  1. Make sure Cursor is fully closed (Task Manager > Details, no Cursor.exe).
  2. Press Win + R, paste this exactly, and press Enter: "%LOCALAPPDATA%\Programs\cursor\Cursor.exe" --no-sandbox
  3. Does Cursor open normally this way? (Please only use this for the test, not as your everyday way to start Cursor, since it turns off a security feature.)
  4. Which security or endpoint software is installed (for example HP Sure Click / Wolf Security, Sandboxie, CrowdStrike, Carbon Black, an AppLocker or Intune policy), and did it update or change in the last few days?
  5. Is Cursor started as administrator, or from a shortcut with “Run as administrator” ticked?
  6. When it fails, does any small dialog appear, even briefly, saying “The window terminated unexpectedly”?

If step 3 works for you, the fix is on the security software side: ask IT (or do it yourself if it is your machine) to add Cursor to its trusted or allowed applications list, using the path %LOCALAPPDATA%\Programs\cursor\Cursor.exe, then start Cursor normally again.

13

Step 3 does work, but so does passing the --disable-gpu flag, too. In fact, every launch attempt I make via PowerShell works. What doesn’t work is launching via the Cursor shortcut (taskbar/start menu).

Fwiw, I used Microsoft Copilot to help me look under various rocks to see if security software (Defender & AppLocker, in my case) was blocking this, but I couldn’t find any security-related events for this. My laptop is an HP and the splash screen on boot shows “HP Wolf Security”, but that app and Sure Click are not installed and I cannot find any running services related to them.

14

Oh, and to clarify @Colin – I mean literally just running cursor in PowerShell launches successfully.

The only time I can launch from the shortcut is after I first boot/log into Windows. If I close and attempt to reopen Cursor later that way, it crashes immediately.

18

Hi Cursor, I’m also seeing this problem.

If I launch Cursor from PowerShell:

& 'C:\Program Files\cursor\Cursor.exe'

I get:

(node:26948) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `Cursor --trace-deprecation ...` to show where the warning was created)

[26948:0917/180252.999:ERROR:content\browser\gpu\gpu_process_host.cc:1011] GPU process launch failed: error_code=21
[26948:0917/180253.296:ERROR:content\browser\gpu\gpu_process_host.cc:1011] GPU process launch failed: error_code=21
[26948:0917/180253.408:ERROR:content\browser\gpu\gpu_process_host.cc:1011] GPU process launch failed: error_code=21
[26948:0917/180253.990:ERROR:content\browser\gpu\gpu_process_host.cc:1011] GPU process launch failed: error_code=21
[26948:0917/180254.042:ERROR:content\browser\gpu\gpu_process_host.cc:1011] GPU process launch failed: error_code=21
[26948:0917/180254.120:ERROR:content\browser\gpu\gpu_process_host.cc:1011] GPU process launch failed: error_code=21
[26948:0917/180254.120:FATAL:content\browser\gpu\gpu_data_manager_impl_private.cc:418] GPU process isn't usable. Goodbye.

main.log is created, but it is 0 bytes (i.e. empty).

There is, however, a crash dump created each time under:

%USERPROFILE%\AppData\Roaming\Cursor\Crashpad\reports

I’ve attached the corresponding .dmp file as a ZIP file

The only way I can get cursor to start is if I run:

& 'C:\Program Files\cursor\Cursor.exe' --no-sandbox

52615730-66c8-4361-9141-1fd1377f08c9.zip (205.1 KB)

23

Hey @prynhart, thanks for the log and the crash dump, that was very helpful!

Your dump shows the same thing we are seeing for the other two people in this thread: Windows refuses to start Cursor’s protected helper processes (the GPU process launch failed: error_code=21 lines), and after six refusals Cursor gives up and exits. That is why main.log stays empty and only a crash dump is left. The dump also shows this is a company-managed PC (a NinjaOne agent is installed), and since everything works the moment the sandbox is off, something on the machine is interfering with how Windows hands out process tokens.

To narrow it down, could you tell us:

  1. Press Win + R, type winver, press Enter, and paste the full “OS Build” line (for example 26200.9448).
  2. Open Settings > Windows Update > Update history and list the updates installed since 8 September, with their dates.
  3. Open Windows Security > Account protection. Is there an “Administrator protection” section, and is it On?
  4. Does Visual Studio Code (if it is installed on this PC) start normally from the Start menu right now? It uses the same protected-process design, so this tells us whether the problem is specific to Cursor.
  5. Which antivirus or endpoint tool does NinjaOne deploy on this PC (for example Bitdefender, SentinelOne, Defender for Endpoint), and did it update in the last week?
  6. Your PATH mentions two Cursor installs, C:\Program Files\cursor and %LOCALAPPDATA%\Programs\cursor. Which one is on your Start menu, and did the Program Files one get to 3.20.21 through the in-app update or a fresh install?

One more test that helped another user: uninstall Cursor, install 3.20.21 fresh from Cursor · Download, and start it from the Start menu. Does it open without --no-sandbox? Your settings and chats are kept.

Until this is sorted, if you need Cursor working daily without typing the flag, create the file %USERPROFILE%\.cursor\argv.json (or edit it if it exists) and add "disable-chromium-sandbox": true inside the braces, then start Cursor normally. This turns off the same protection as --no-sandbox, so please treat it as temporary.

24

Hi @Colin,

Thanks very much for looking into this and for your comprehensive analysis of the crash dump. Here are the requested details.

Windows version

Windows 11 Enterprise, Version 25H2 (OS Build 26200.9448).

Updates installed since 8 September

The significant updates are listed below. I have grouped the repeated Defender security-intelligence and Windows App Runtime entries.

8 September: 2026-09 Security Update, KB5124008, OS Build 26200.9445
8 September: 2026-09 .NET Framework Security Update, KB5126052
8 September: Windows Malicious Software Removal Tool x64 v5.145, KB890830
8 September: 2026-09 .NET 8.0.31 Security Update for x64 Client, KB5126104
8–17 September: Multiple Microsoft Defender security-intelligence updates, KB2267602
10, 13, 14, 16 and 19 September: Multiple Microsoft Windows App Runtime updates
13 September: Intel Bluetooth driver update, version 24.50.0.4
13 September: Lenovo SoftwareComponent driver update, version 26.9.0.20
13 September: Lenovo System driver update, version 26.7.0.7
14 September: 2026-09 Security Update (Hotpatch capable), KB5129241, OS Build 26200.9448
17 September: Microsoft Defender Antivirus antimalware platform update, KB4052623, version 4.18.26080.4

Administrator protection

There is no “Administrator protection” section under Windows Security > Account protection. The page only shows Windows Hello and Dynamic lock.

Visual Studio Code

Visual Studio Code starts normally from the Start menu without any additional flags.

Its version information is:

VS Code: 1.137.0, user setup
Electron: 42.10.0
Chromium: 148.0.7778.280
Node.js: 24.18.1
OS: Windows_NT x64 10.0.26200

Antivirus and endpoint protection

Windows Defender Antivirus is installed. Its current versions are:

Product version: 4.18.26080.4
Engine version: 1.1.26080.3
Security-intelligence version: 1.459.258.0
Security intelligence last updated: 18 September 2026 at 2:26 am

The computer also has the Microsoft Defender for Endpoint plug-in for WSL version 1.26.813.1, installed on 21 August 2026.

The Defender antimalware platform updated on 17 September at 9:52 pm. However, my first recorded Cursor failure occurred earlier that day, at approximately 6:02 pm. Therefore, that platform update occurred after the problem had already started. The Windows hotpatch KB5129241 was installed on 14 September.

Cursor installations and clean-install test

Good question regarding the two Cursor installations!

I was originally using the per-user installation:

C:\Users\prynhart\AppData\Local\Programs\cursor\Cursor.exe

When that stopped working, I tried uninstalling and reinstalling Cursor, but the problem remained. I then performed a fresh system-wide installation of version 3.20.21 under:

C:\Program Files\cursor\Cursor.exe

Both Cursor Start-menu shortcuts point to the system-wide executable, so the Start menu launches the fresh 3.20.21 installation.

As part of the clean-install testing, I removed everything under both of the following locations:

C:\Users\prynhart\AppData\Local\Programs\cursor
C:\Users\prynhart\AppData\Roaming\Cursor

I used Sysinternals Process Monitor (Procmon) to identify the local files being accessed by the Cursor executables before removing them.

Both installations exhibited the same behaviour when tested: Cursor does not open normally but works when launched with --no-sandbox. The fresh system-wide 3.20.21 installation also fails when launched normally from the Start menu.

25

Hi again,

An update! Well the system-wide Cursor 3.20.21 installation is now opening normally from the Start menu without --no-sandbox, even though I have not made any further changes to Cursor :-/

I checked the following:

  • Cursor is still version 3.20.21, and the executable has not changed since 13 September.
  • My argv.json file does not disable the Chromium sandbox.
  • None of the running Cursor processes includes --no-sandbox.
  • Windows has not restarted since 17 September at 9:47 am, which was before the failure I recorded at approximately 6:02 pm that day.

However, a few updates were installed during that period:

  • 17 September, 9:52 pm: Defender antimalware platform KB4052623, version 4.18.26080.4
  • 19 September, 1:23–1:27 am: Several Microsoft Windows App Runtime 2 component updates
  • 19 September, 1:41 am: Defender security intelligence KB2267602, version 1.459.280.0

It looks as though a live Windows or security update must have cleared this problem.

Thanks again for the help!

Patrick

29

Hey @prynhart

Thanks for confirming. That’s looking like it’s the case.

Would love to hear from @Ketan_Pardeshi and @tbowersoxbt also to know if it’s fixed for them, after making sure they’re up to date on security updates!

30

I was about to write that all was well for me so far today, but after testing an open/close/open to be 100% sure, I just reproduced the issue again. :upside_down_face:

There were some Windows Defender/Security Intelligence updates installed on my PC today, and a Cursor update, too.

Seems like I can get Cursor to open successfully via the Start icon once per session. If I close it then open it again, it’ll flash open and close immediately. Restarting my computer fixes it.

But, I can still open it reliably via the cursor CLI command in PowerShell 100% of the time. It’s so bizarre.

35

Hey all!

It looks like this might be an issue affecting more than just Cursor (and Grok Bot), but all applications which rely on Chromium sandbox tokens.

KB5124008 seems to be where issues started, which may have been carried forward by KB5129195 / KB5129241. I have KB5129195 installed on my Windows device and do not experince the issue with crashing.

Uninstalling KB5124008 seems to resolve the issue on the affected device, although on managed devices that is probably easier said than done.

I have to dig into this a bit more.