[Error] unhandlederror-Cannot read properties of undefined (reading 'add')
- Dominant language
- TypeScript
- Stars
- 193k
- Forks
- 42.4k
- PR merge metrics
- PR metrics pending
Description
## Error Message
````
unhandlederror-Cannot read properties of undefined (reading 'add')
````
## Stack Trace
at (anonymous) ([./src/vs/workbench/contrib/output/common/outputChannelModel.ts:500:31](https://github.com/microsoft/vscode/blob/e4c7e7b1d6d060162f4aa7f8225271b67ce1df75/src/vs/workbench/contrib/output/common/outputChannelModel.ts#L500))
at async ([./src/vs/base/common/async.ts:1946:4](https://github.com/microsoft/vscode/blob/e4c7e7b1d6d060162f4aa7f8225271b67ce1df75/src/vs/base/common/async.ts#L1946))
Raw Stack Trace (minified)
````
TypeError: Cannot read properties of undefined (reading 'add') at out/vs/sessions/sessions.desktop.main.js:3366:912 at async out/vs/sessions/sessions.desktop.main.js:434:84814
````
## Details
| Property | Value |
| --- | --- |
| Bucket ID | [`22431e0d-e894-cc75-9853-c908d25e574b`](https://errors.code.visualstudio.com/bucket/22431e0d-e894-cc75-9853-c908d25e574b?product=VSCode&extension=core&commit=e4c7e7b1d6d060162f4aa7f8225271b67ce1df75) |
| Version | 1.131.0 |
| Commit | [`e4c7e7b1`](https://insiders.vscode.dev/github/microsoft/vscode/tree/e4c7e7b1d6d060162f4aa7f8225271b67ce1df75) |
| Last Seen | Thu Jul 30 2026 23:45:37 GMT+0000 (Coordinated Universal Time) |
| Platforms | Windows, Mac |
| Product | VSCode |
---
*This issue was automatically created from the VS Code Errors Dashboard*
Contributor guide
Assessment
This issue has not been assessed yet.