[Bug]: clicked the "diff" button to open diff in right panel and UI crashed with "duplicate id" error

[rf-molsson]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

I clicked on the "right panel" icon and then clicked the "diff" button

Expected behavior

show diff

Actual behavior

T3 Code (Nightly) 0.0.39-nightly.20260903.1267
Path: /58a9da26-4126-4afa-b2bb-f00273e76ef9/8e83fee8-8cc8-44d3-b875-12eb92541f90
Time: 2026-09-03T13:15:03.887Z

Error: CodeView.addItem: duplicate id ""
at e.appendItemsInternal (t3code://app/assets/diffFileContents-CXLF0KVR.js:1:17546)
at e.setItems (t3code://app/assets/diffFileContents-CXLF0KVR.js:1:17157)
at t3code://app/assets/diffFileContents-CXLF0KVR.js:1:49039
at Uc (t3code://app/assets/dist-Bx7Ty0w9.js:8:91657)
at sl (t3code://app/assets/dist-Bx7Ty0w9.js:8:96128)
at xl (t3code://app/assets/dist-Bx7Ty0w9.js:8:104924)
at sl (t3code://app/assets/dist-Bx7Ty0w9.js:8:96115)
at xl (t3code://app/assets/dist-Bx7Ty0w9.js:8:104924)
at sl (t3code://app/assets/dist-Bx7Ty0w9.js:8:96115)
at xl (t3code://app/assets/dist-Bx7Ty0w9.js:8:104924)

the worst part is that when I click "try again" or "reload app" buttons, then it just immediately crashes again

Impact

Pretty disruptive since T3 just crashes again immediately when I relaunch it, so I have no way using or upgrading it etc??

Version or commit

0.0.39-nightly.20260903.1267

Environment

macos

Logs or stack traces

Screenshots, recordings, or supporting files

No response

Workaround

No response