Cursor freezes after AI-edit tool call — resolved by removing 'showTabs: single'

Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Cursor freezes immediately after the AI applies an edit to a file. The UI becomes unresponsive and must be force-quit. This happens consistently on macOS 15.6.1 (Sequoia) in the latest version of Cursor.

The developer console shows only:
WARN ToolCallEventService: Tracked tool call end - toolu_vrtx_01AF3W9nBZeKwh36MoQaJW4w

No save hooks, formatters, or extensions are active. Hardware acceleration is disabled. The issue occurs even in new workspaces and empty projects.

After extensive testing, I traced the problem to a specific user setting in the file:
~/Library/Application Support/Cursor/User/settings.json

The following line, when present, causes Cursor to hang immediately after an AI edit:

“workbench.editor.showTabs”: “single”

If this line is removed (or if the setting is changed to its default), the freeze no longer occurs.

This suggests that Cursor’s AI edit logic or editor layout refresh routines are not handling the “single” tab mode correctly.

Steps to Reproduce

1.	Add the following line to your settings.json file:

“workbench.editor.showTabs”: “single”
2. Restart Cursor.
3. Ask the AI to make any change to a file (for example, “add a comment at the top”).
4. Cursor will freeze immediately after the AI applies the edit.

Optional verification:
1. Remove or comment out the line above.
2. Restart Cursor.
3. Perform the same AI edit again.
4. Cursor no longer freezes.

Expected Behavior

Cursor should handle AI-applied edits normally regardless of tab display mode. The “single tab” mode should not trigger a freeze in the editor.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.54
VSCode Version: 1.99.3
Commit: 5c17eb2968a37f66bc6662f48d6356a100b67be0
Date: 2025-10-21T19:07:38.476Z (4 days ago)
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.6.0

Additional Information

Additional information
• No third-party extensions or formatters enabled.
• Hardware acceleration disabled.
• The issue is fully reproducible on any workspace when “workbench.editor.showTabs” is set to “single”.
• Developer console shows only the ToolCallEventService warning at the time of the freeze.
• Removing or changing that line immediately resolves the problem.

Does this stop you from using Cursor

Yes - Cursor is unusable

10 Likes
2

Hey, thanks for the report and for finding the exact cause. That really helps.

The conflict between workbench.editor.showTabs: "single" and the AI editing process is definitely a bug that needs to be fixed. I’ll pass it to the engineering team.

For now, removing this setting or using the default value should let you use Cursor normally.

Thanks for digging into this so thoroughly, it’s super helpful.

2 Likes
4

Thanks @Michael_T! I encountered and reported the same bug. Your workaround works for me also.

5

I have the exact same issue (MacOS) and I also determined it was exactly this setting that was causing the issue: "workbench.editor.showTabs": "single". When none or multiple, I don’t have any issue.

It was indeed happening exactly when the agent made (or attempt to make) any modification to a file.

3 Likes
6

Same issue here. The suggested solution fixed it, but we should be able to use the single tab without the code editor freezing.

7

Same issue here, and the suggested solution fixed it. Thank you very much! You saved me a lot of time on fixing this.

8

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

The setting “workbench.editor.showTabs”: “single” in settings.json causes AI coding assistants to malfunction when making file edits, resulting in failed search/replace operations and inconsistent file modification behavior.

Configuration causing issue:
{
“workbench.editor.showTabs”: “single”
}

Steps to Reproduce

Steps to reproduce:

  1. Set “workbench.editor.showTabs”: “single” in settings.json
  2. Try to use AI assistant to edit files
  3. Observe failed or inconsistent edit operations

Expected Behavior

Expected: AI assistants should work normally regardless of tab configuration.
Actual: AI assistants fail to make file edits consistently when single tab mode is enabled.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.54
VSCode Version: 1.99.3
Commit: 5c17eb2968a37f66bc6662f48d6356a100b67be0
Date: 2025-10-21T19:07:38.476Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 25.0.0

For AI issues: which model did you use?

Auto

Does this stop you from using Cursor

Yes - Cursor is unusable

9

Same issue…

10

Thank you so much for finding the cause. This was so anoying for me. However, I would like to use a single tab feature so fixing this is really important for me.