Renderer crashes (code 5) every 5-10 min on macOS 2.6.13

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Renderer crashes with code 5 every 5-10 minutes on a large Nx monorepo workspace. 8 crashes in a single session today. Other Cursor windows (smaller projects) on the same machine don’t crash.

DevTools console captured the error right before each crash:

[transport] Connect error in unary AI
connect ConnectError: [not_found] Error
at t (workbench.desktop.main.js:43782:42958)
at async Object.getBackgroundComposerChangesHash (workbench.desktop.main.js:34081:4386)
at async workbench.desktop.main.js:49773:37585
at async zid.__fetchOptimizedDiffDetailsAndUpdateImpl (workbench.desktop.main.js:49773:34255)

main.log also shows the SQLite nested transaction bug before crashes:

[AgentAnalyticsOperationsMainService] Error marking commits as scored: SQLITE_ERROR: cannot start a transaction within a transaction

Process Explorer shows Renderer at 42% CPU and GPU at 40% CPU at baseline with no active operations.

Steps to Reproduce

  1. Open a large monorepo workspace (~2GB node_modules, 8 MCP servers configured)
  2. Use agent mode with file edits
  3. Renderer crashes within 5-10 minutes, consistently
  4. Session spawned 14 windows as Cursor kept recreating the renderer after each crash

Expected Behavior

Agent sessions should remain stable regardless of workspace size.

Operating System

MacOS

Version Information

Version: 2.6.13
VSCode Version: 1.105.1
Commit: b0d3cbf734cedc1130071180885d53c060e3dd9d04b4b46b459fe3a885d3dcee
Stable

For AI issues: which model did you use?

Multiple models - crash is model-independent

Additional Information

Full crash timeline from main.log (all code 5):

2026-03-08 00:43 - crash 1
2026-03-08 09:53 - crash 2
2026-03-08 09:59 - crash 3 (6 min gap)
2026-03-08 10:03 - crash 4 (4 min gap)
2026-03-08 10:12 - crash 5 (9 min gap)
2026-03-08 10:18 - crash 6 (6 min gap)
2026-03-08 11:12 - crash 7
2026-03-08 11:20 - crash 8 (8 min gap)

Team members on Cursor 2.5.x do NOT experience this crash.

The getBackgroundComposerChangesHash → ConnectError [not_found] stack trace appears to be the direct trigger - the background composer tries to fetch diffs, gets a “not found” error, and crashes the renderer.

Related: Renderer crashes (code 5) during long agent sessions due to SQLite nested transaction bug

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

screenshot demonstrating the issue:

Hi @oferlmntr!

Thanks for the report. We’ve been working to improve performance issues in 2.6. Could you let us know if you’re still seeing the crash in v2.6.18?

I had the same crash in 2.6.13 & 14, just updated to 2.6.18. It seems to not crash for me anymore.