When opening an AL (Business Central) project folder in Cursor IDE, the extension host process crashes repeatedly with Windows error code -1073740791 (STATUS_STACK_BUFFER_OVERRUN). This causes the error message “Extension host terminated unexpectedly 3 times within the last 5 minutes.”
A structurally identical AL project (Project1) with the same extensions, settings, and file types opens successfully without any crashes. Only Project2 exhibits this crash behavior.
Steps to Reproduce
Open Cursor IDE (version 2.4.35)
File > Open Folder…
Open the problematic AL project folder (Project2)
Wait for extensions to activate
Observe: Extension host crashes 3 times rapidly, then shows error dialog
Comparison test (works):
Open a different AL project folder (Project1) with identical structure and extensions
Observe: Opens successfully without crashes
Expected Behavior
The project should open without extension host crashes, similar to other structurally identical AL projects.
0xC0000409 is stack corruption in native code, most likely coming from ms-dynamics-smb.al (based on the timings in the logs).
A couple of questions to figure out whether this is a Cursor issue or extension-related:
You mentioned you tried opening the same project in VS Code. Does it work there without crashing?
Try opening the project with extensions disabled: cursor --disable-extensions. Does it still crash?
It’s also worth trying to delete the workspace storage for this project: %APPDATA%\Cursor\User\workspaceStorage (delete the folders related to Project2, Cursor will recreate them, make a backup first).
Let me know the results and I’ll escalate to the team if it’s Cursor-specific.
Thanks for the additional questions and information.
What I’ve done:
(When I mention a crash I mean the “Extension host termindated unexpectedly 3 times within the last 5 minutes.” shows up)
12/02/2026 installed cursor again from the website downloads.
Tried again, still crashes for the same repo.
Open in VSCode, same set of extensions: no crash
Similar project, but in Cursor, same set of extensions: no crash
Deleted the most recent workspacestorage folder for the project (checked the files in the folder to make sure it was that one since they are guids), still crashes.
Installed new versions, available since today (13/02/2026)
Still crashes for the same repo.
Version: 2.4.36 (system setup)
VSCode Version: 1.105.1
Commit: f9919bf991f247689f9ead605b5c5a3239a2a790
Date: 2026-02-12T21:00:33.976Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26200
Checked the workspacestorage for any folders (also older ones) referring to the project and deleted those. Still crashes.
Disabled the ms-dynamics-smb.al extension and checked the latest crash logs, might be on to something here:
Timeline (08:54:50 → 08:54:52)
08:54:50.276 – Extension host starts for ProjectWithCrash\App.
08:54:50–52 – Eager extensions activate (no ms-dynamics-smb.al in the list):
08:54:52.258 – Last successful activation: anysphere.cursor-agent-exec (took 1806 ms).
08:54:52.551 – Extension host terminates: “renderer closed the MessagePort” (pids 50368, 33152 exit with code 0 in the log; the actual crash is in main.log as -1073740791).
So the crash happens ~300 ms after the last logged activation, still in the same extension host that had just finished eager activation.
Conclusion from this log
With ms-dynamics-smb.al disabled:
The last extension that completed activation before the crash is anysphere.cursor-agent-exec (Cursor built-in).
The crash occurs right after “Eager extensions activated” and that activation; there is no later _doActivateExtension for another extension before “Extension host terminating”.
So the trigger is either:
anysphere.cursor-agent-exec (or something it does right after activation), or
Another Cursor/IDE component that runs in the same window right after eager activation (e.g. file watcher or other built-in code), rather than another marketplace extension.
That fits with main.log still showing extension host crash -1073740791 (STATUS_STACK_BUFFER_OVERRUN) and a separate file watcher crash -1073741819: the problem can be in Cursor’s own process or a built-in extension, not only in the AL extension.
Conclusion:
You can add something like:
With ms-dynamics-smb.al disabled, the same extension host crash still occurs when opening the same project.
In exthost.log, the last successful activation before “Extension host terminating” is anysphere.cursor-agent-exec; the crash happens ~300 ms later with no other extension activation in between.
Workspace in the log: b74efdf768d931f18843b20f2fe1f4f4 (folder: ProjectWithCrash\App).
Cursor suggested disabling the cursor agent and cursor agent exec, did that for that repo, closed cursor, opened it again, but still crashed.
Read and analyzed the new logs: New session: 20260213T090547
main.log
09:05:52.695 – Extension host pid 8640 crashed with code -1073740791 (STATUS_STACK_BUFFER_OVERRUN). Same crash as before.
09:05:53.107 – “Extension host terminating: renderer closed the MessagePort” (main.log shows the actual crash of pid 8640 at 09:05:52.695).
So the crash happens during or right after the batch that starts with Project Manager and GitLens. There is no “Extension activated success” for:
alefragnani.project-manager
eamodio.gitlens
esbenp.prettier-vscode
Gruntfuggly.todo-tree
PKief.material-icon-theme
streetsidesoftware.code-spell-checker
usernamehw.errorlens
So the failure occurs while one of these is activating (or in the ~180 ms after the last “activated success” we do see).
So this seems like an endless circle of referring to the next extension that is not yet de-activated.
Seems like the issue is just activating any extension.
I cloned the repo on a new location on my PC and opened it in cursor:
Crashes!
This is worrying me, I was hoping a local file or setting or older metadata tied to the repo was causing the issue, but even in the new clone I cannot work on the app anymore in Cursor
