[Regression] [Error] unhandlederror-Cannot read properties of undefined (reading 'uri')

[vs-code-engineering]

Error Message

unhandlederror-Cannot read properties of undefined (reading 'uri')

Stack Trace

    at jE.createModifiedCellDiffInfo (./src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingModifiedNotebookEntry.ts:700:0)
    at createModifiedCellDiffInfo (./src/vs/workbench/contrib/chat/browser/chatEditing/notebook/helpers.ts:262:24)
    at JMo (./src/vs/workbench/contrib/chat/browser/chatEditing/notebook/helpers.ts:259:7)
    at adjustCellDiffAndOriginalModelBasedOnCellAddDelete (./src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingModifiedNotebookEntry.ts:323:0)
    at jE.mirrorNotebookEdits (./src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingModifiedNotebookEntry.ts:322:0)
    at _._deliver (./src/vs/base/common/event.ts:1364:12)
    at _._deliverQueue (./src/vs/base/common/event.ts:1375:8)
    at _.fire (./src/vs/base/common/event.ts:1399:8)
    at wwe.value (./src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts:301:29)
    at OMi._deliver (./src/vs/base/common/event.ts:1364:12)
    at OMi.fire (./src/vs/base/common/event.ts:1395:8)
    at OMi.resume (./src/vs/base/common/event.ts:1544:11)
    at voe.applyEdits (./src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts:671:26)
    at voe.reset (./src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts:463:7)
    at uU.update (./src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts:316:22)
    at async M8.doUpdateModel (./src/vs/workbench/services/workingCopy/common/storedFileWorkingCopy.ts:715:0)
    at async M8.resolveFromContent (./src/vs/workbench/services/workingCopy/common/storedFileWorkingCopy.ts:678:0)
    at async M8.resolveFromFile (./src/vs/workbench/services/workingCopy/common/storedFileWorkingCopy.ts:618:0)
    at async CFe.doResolve (./src/vs/workbench/services/workingCopy/common/storedFileWorkingCopyManager.ts:564:0)
    at async CFe.reload (./src/vs/workbench/services/workingCopy/common/storedFileWorkingCopyManager.ts:453:0)

Raw Stack Trace (minified)

TypeError: Cannot read properties of undefined (reading 'uri')     at jE.createModifiedCellDiffInfo (out/vs/workbench/workbench.desktop.main.js:3309:8877)     at out/vs/workbench/workbench.desktop.main.js:3308:95340     at Array.forEach (<anonymous>)     at JMo (out/vs/workbench/workbench.desktop.main.js:3308:95298)     at out/vs/workbench/workbench.desktop.main.js:3309:1281     at Array.forEach (<anonymous>)     at jE.mirrorNotebookEdits (out/vs/workbench/workbench.desktop.main.js:3309:1267)     at _._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at _._deliverQueue (out/vs/workbench/workbench.desktop.main.js:405:3358)     at _.fire (out/vs/workbench/workbench.desktop.main.js:405:3693)     at wwe.value (out/vs/workbench/workbench.desktop.main.js:1922:5331)     at OMi._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at OMi.fire (out/vs/workbench/workbench.desktop.main.js:405:3588)     at OMi.resume (out/vs/workbench/workbench.desktop.main.js:405:4877)     at voe.applyEdits (out/vs/workbench/workbench.desktop.main.js:1922:11870)     at voe.reset (out/vs/workbench/workbench.desktop.main.js:1922:8595)     at uU.update (out/vs/workbench/workbench.desktop.main.js:1071:81091)     at async M8.doUpdateModel (out/vs/workbench/workbench.desktop.main.js:1071:66883)     at async M8.resolveFromContent (out/vs/workbench/workbench.desktop.main.js:1071:66491)     at async M8.resolveFromFile (out/vs/workbench/workbench.desktop.main.js:1071:65825)     at async CFe.doResolve (out/vs/workbench/workbench.desktop.main.js:2442:16928)     at async CFe.reload (out/vs/workbench/workbench.desktop.main.js:2442:15859)     at async Object.factory (out/vs/workbench/workbench.desktop.main.js:2442:14263)

Details

Property	Value
Bucket ID	a8847c1f-ed4e-1148-b0a0-2703c5faf4e0
Version	1.122.0
Commit	7090241a
Last Seen	Wed May 27 2026 22:34:22 GMT+0000 (Coordinated Universal Time)
Platforms	Windows, Mac
Product	VSCode

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This issue was automatically created from the VS Code Errors Dashboard

[vs-code-engineering]

Regression Details

• Product: VSCode
• Regression type: spike (5x increase)
• Spike factor: 5x (4 users → 20 users)

Commit Range

• Last stable without spike: 1.122.0
• Current insider with spike: 1.122.0-insider
• Commit range: compare

Deminified Stack

chatEditingModifiedNotebookEntry.ts:700 → createModifiedCellDiffInfo
notebook/helpers.ts:262 → createModifiedCellDiffInfo
notebook/helpers.ts:259
chatEditingModifiedNotebookEntry.ts:323 → adjustCellDiffAndOriginalModelBasedOnCellAddDelete
chatEditingModifiedNotebookEntry.ts:322 → mirrorNotebookEdits
event.ts (fire/deliver chain)

The error occurs when mirrorNotebookEdits processes cell changes and attempts to read .uri from an undefined cell diff entry.

Generated by errors-regression-scan · ● 50.2M · ◷