Chat no longer works

Type: Bug

The Github Copilot's Chat does not work since about 15-20 hours ago (it worked before that): everything typed into Chat, there is no response. Github CLI works well. Here is some messages from View->Output->Github Copilot Chat when I typed something like "there" in Chat.

CopilotCLIChatSessionContentProvider] listSessions took 26.96400000154972ms
2026-09-11 11:15:55.044 [warning] Task API list-for-repo failed: 404 (owner=BenjaminZhu, repo=MyWork, taskId=n/a); body={"documentation_url":"https://docs.github.com/rest","message":"not found"}
2026-09-11 11:15:55.054 [warning] Failed to fetch tasks for BenjaminZhu/MyWork: TaskApiError: Task API request failed: 404

VS Code version: Code 1.136.1 (a44adf7f53e00964ab890f9f8758a334f1fc15bc, 2026-09-03T05:06:41Z)
OS version: Windows_NT x64 10.0.19045
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Core(TM) i7-7660U CPU @ 2.50GHz (4 x 2496)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x8086, DEVICE=0x5926 [Intel(R) Iris(R) Plus Graphics 640], DRIVER_VENDOR=Intel, DRIVER_VERSION=27.20.100.8682 *ACTIVE*
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.5794
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)|15.92GB (5.84GB free)|
|Process Argv|. --crash-reporter-id 2786c153-ecbe-4bbf-960a-cdad98ccd8ec|
|Screen Reader|no|
|VM|0%|
Extensions (11)

Name|Identifier|Author|Version
---|---|---|---
Office Viewer|cweijan.vscode-office|cweijan|4.2.0
GitLens — Git supercharged|eamodio.gitlens|eamodio|19.1.0
Overleaf Workshop|iamhyc.overleaf-workshop|iamhyc|0.15.10
LaTeX Workshop|james-yu.latex-workshop|James-Yu|10.18.0
Python Debugger|ms-python.debugpy|ms-python|2026.6.0
Python|ms-python.python|ms-python|2026.4.0
Pylance|ms-python.vscode-pylance|ms-python|2026.3.1
Python Environments|ms-python.vscode-python-envs|ms-python|1.36.0
YAML|redhat.vscode-yaml|redhat|1.24.0
Microsoft 365 Agents Toolkit|teamsdevapp.ms-teams-vscode-extension|TeamsDevApp|6.16.0
Smart PDF Editor|vnstock.smart-pdf-editor|vnstock|0.0.4

A/B Experiments

```
vsliv368cf:30146710
vswsl492cf:30256860
binariesv615:30325510
f8hc8238:30694864
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
478i5457:31544283
cloudbuttont:31379625
42190218_ostrepl:31403339
839jf696:31457053
ddidtcf:31399634
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
8hhj4413:31478653
cp_cls_c_1081:31454833
conptydll_true:31498968
e9c30283:31461165
46204921:31447328
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
23c7c724:31520045
ddid_t:31478206
hmra_i5g22:31518061
l_j1ci3728:31580635
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
a1ije391_t:31540920
jbcp_cls_pctr_t:31531130
cp_intellij_t_nes:31548657
gf14b233:31526830
ahp-both-windows:31556933
ihg5j128:31534457
9gg7f176:31542112
enable_editor_pane_layout:31569726
allow-none:31555437
36h42362:31564511
c7c27ce7:31554789
1h923230:31564177
1532g621_copy:31554320
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
switchtoauto:31559321
nemo-v2:31565334
0c1h4866:31566224
vrbsty_fls:31561059
session-mark-done:31558131
5b8j3302:31564601
mangle-name-treatment:31572634
intellij_nes_preview_t:31580086
multiv2:31574985
2bfb8b39:31576696
permission_prompt_control:1332567
ccr_pr_nudge_auto_review:1319472
vsc_wsm_c:1340633
eh853263:1370294
1g5a5742:1379227
3aced641:1389836

```