Got Error Open "New Chat Window" GitHub Copilot

Type: Bug

2026-09-01 13:59:35.827 [error] [Window] Error: Not allowed to create elements in child window JavaScript context. Always use the main window so that "xyz instanceof HTMLElement" continues to work.
at e.document.createElement (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1488:142302)
at y7i.createDormantHost (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3070:34681)
at y7i.activate (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3070:34293)
at y7i.register (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3070:33943)
at _Ge.register (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3070:35665)
at Ub.render (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3070:54114)
at eP.createEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3321:12149)
at eP.create (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1101:50914)
at nHe.doCreateEditorPane (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1375:34129)
at nHe.doShowEditorPane (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1375:33622)
at nHe.doOpenEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1375:32869)
at nHe.openEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1375:31879)
at vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1488:75771
at kS.doShowEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1488:76019)
at kS.doOpenEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1488:75517)
at kS.openEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1488:74354)
at eIe.openEditor (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1980:45588)
at async Qje.openSession (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:3709:2407)
at async K.run (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:1228:44352)
at async Ts.runAction (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:439:31533)
at async Ts.run (vscode-file://vscode-app/c:/Users/ouii/AppData/Local/Programs/Microsoft%20VS%20Code/08d4889f9e/resources/app/out/vs/workbench/workbench.desktop.main.js:439:31433)

VS Code version: Code 1.135.0 (08d4889f9ec4a1685d257b9b95de036c8e1ce1e5, 2026-08-25T14:26:52Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Core(TM) i7-10610U CPU @ 1.80GHz (8 x 2304)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x8086, DEVICE=0x9b41 [Intel(R) UHD Graphics], DRIVER_VENDOR=Intel, DRIVER_VERSION=31.0.101.2114 *ACTIVE*
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8972
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|31.73GB (15.85GB free)|
|Process Argv|--crash-reporter-id 5bb1c545-8421-4828-9573-d37030188cc9|
|Screen Reader|no|
|VM|0%|
Extensions (2)

Name|Identifier|Author|Version
---|---|---|---
Dart|dart-code.dart-code|Dart-Code|3.140.0
Flutter|dart-code.flutter|Dart-Code|3.140.0

A/B Experiments

```
vsliv368:30146709
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
gh487529:31544284
cloudbuttont:31379625
3efgi100_wstrepl:31403338
839jf696:31457053
ec5jj548:31422691
diffpatch-lysithea-24-production:31576352
cp_cls_t_966_ss:31526232
4je02754:31466945
8hhj4413:31478653
ge8j1254_inline_auto_hint_haiku:31490510
cp_cls_c_1081:31454833
conptydll_true:31498968
e9c30283:31461165
46204921:31447328
ei9d7968:31496641
nes-extended-on:31455476
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
23c7c724:31520045
ddid_c:31478207
hmra_i5g22:31518061
ja75b849:31575055
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
jh5f2457_c:31540921
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31548657
jf4hg949:31526829
ahp-both-windows:31556933
ihg5j128:31534457
f412h606:31551416
7g2b5551:31542111
enable_editor_pane_layout:31569726
allow-none:31555437
ac562147:31564510
c7c27ce7:31554789
1h923230:31564177
1532g621_copy:31554320
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
a1hcc538:31559322
0c1h4866:31566224
vrbsty_tr:31561058
session-archive:31558132
5b8j3302:31564601
mangle-name-control:31572633
multiv2:31574985

```