[macOS] Agent Window crashes renderer — setSideBarPosition(undefined) in 3.2.0-pre.48

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Where does the bug appear (feature/product)?

Cursor CLI

Describe the Bug

Assertion Failed: Argument is undefined or null.
at Yjb.setSideBarPosition (workbench.desktop.main.js:43318:43735)
at qBl.updateSidebarPositionFromAgentLayoutStorage (workbench.desktop.main.js:43318:101042)

Steps to Reproduce

Assertion Failed: Argument is undefined or null.
at Yjb.setSideBarPosition (workbench.desktop.main.js:43318:43735)
at qBl.updateSidebarPositionFromAgentLayoutStorage (workbench.desktop.main.js:43318:101042)

Operating System

MacOS

Version Information

Version: 3.2.0-pre.48.patch.0 (Universal)
VSCode Version: 1.105.1
Commit: 1a799c189bae4693c309be8329a4705c3345cd20
Date: 2026-04-20T06:07:04.353Z
Layout: glass
Build Type: Stable
Release Track: Nightly
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.4.0

Does this stop you from using Cursor

No - Cursor works, but with this issue

6

Thanks for reporting this with the stack trace — really helpful for narrowing things down.

I can see the crash is in setSideBarPosition during early startup in the Glass layout, but I wasn’t able to reproduce it on the same Nightly build (3.2.0-pre.48). Could you help me pin down what triggers it?

  1. Does this happen every time you open Cursor, or intermittently?

  2. Did this start after upgrading to pre.48, or was it happening on a prior Nightly build too?

  3. Had you changed your sidebar position (moved it to the left) before this started?

  4. If you can open Developer Tools (Help > Toggle Developer Tools) and check the Console tab after the error appears, a screenshot of the full error stack would be very useful.

This will help us reproduce and fix the underlying timing issue. Thanks!