unexpected status 404 Not Found:

Type: Bug

unexpected status 404 Not Found: The model `gpt-5.5` does not exist or you do not have access to it., url: https://chatgpt.com/backend-api/codex/responses, cf-ray: a38fcd6ffd599a55-CJB, request id: 8fe89502-93c1-405c-b97f-f6ee0eb1c345

VS Code version: Code 1.136.1 (a44adf7f53e00964ab890f9f8758a334f1fc15bc, 2026-09-03T05:06:41Z)
OS version: Windows_NT x64 10.0.20348
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Core(TM) i7-8700T CPU @ 2.40GHz (12 x 2400)|
|GPU Status|2d_canvas: unavailable_software
GPU0: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VENDOR=Microsoft, DRIVER_VERSION=10.0.20348.5020 *ACTIVE*
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.20348.5020
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.20348.5020
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: disabled_software
multiple_raster_threads: enabled_on
opengl: disabled_off
rasterization: disabled_software
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: disabled_software
video_encode: disabled_software
webgl: unavailable_software
webgpu: unavailable_software
webnn: unavailable_software|
|Load (avg)|undefined|
|Memory (System)|15.84GB (9.11GB free)|
|Process Argv|--crash-reporter-id 9117b781-f83d-4bbf-a744-a9436b0f5fe8|
|Screen Reader|no|
|VM|0%|
Extensions (50)

Name|Identifier|Author|Version
---|---|---|---
Markdown Preview Github Styling|bierner.markdown-preview-github-styles|bierner|2.2.0
Tailwind CSS IntelliSense|bradlc.vscode-tailwindcss|bradlc|0.16.0
npm Intellisense|christian-kohler.npm-intellisense|christian-kohler|1.4.5
Path Intellisense|christian-kohler.path-intellisense|christian-kohler|2.10.0
CodeRabbit|coderabbit.coderabbit-vscode|coderabbit|0.21.6
Codex|codexbuild.codex-build|CodexBuild|0.5.7
Codex|davidlaczik.codex|davidlaczik|3.0.0
ESLint|dbaeumer.vscode-eslint|dbaeumer|3.0.34
GitLens — Git supercharged|eamodio.gitlens|eamodio|19.1.0
HTML CSS Support|ecmel.vscode-html-css|ecmel|2.0.14
npm|eg2.vscode-npm-script|eg2|0.3.29
Prettier - Code formatter|esbenp.prettier-vscode|esbenp|12.4.0
Auto Close Tag|formulahendry.auto-close-tag|formulahendry|0.5.15
Auto Rename Tag|formulahendry.auto-rename-tag|formulahendry|0.1.10
shell-format|foxundermoon.shell-format|foxundermoon|7.2.8
Gemini Code Assist|google.geminicodeassist|google|2.100.0
Codex Stats|martinortiz.codex-stats|MartinOrtiz|1.0.4
IntelliCoder|messageai.intellicoder|MessageAI|1.0.1
DotENV|mikestead.dotenv|mikestead|1.0.1
SCSS IntelliSense|mrmlnc.vscode-scss|mrmlnc|0.10.0
Container Tools|ms-azuretools.vscode-containers|ms-azuretools|2.5.0
Docker|ms-azuretools.vscode-docker|ms-azuretools|2.0.0
C# Dev Kit|ms-dotnettools.csdevkit|ms-dotnettools|3.20.207
C#|ms-dotnettools.csharp|ms-dotnettools|2.140.9
.NET Install Tool|ms-dotnettools.vscode-dotnet-runtime|ms-dotnettools|3.1.0
Python Debugger|ms-python.debugpy|ms-python|2026.6.0
Python|ms-python.python|ms-python|2026.7.2026082601
Pylance|ms-python.vscode-pylance|ms-python|2026.3.1
Python Environments|ms-python.vscode-python-envs|ms-python|1.36.0
Dev Containers|ms-vscode-remote.remote-containers|ms-vscode-remote|0.469.0
Remote - SSH|ms-vscode-remote.remote-ssh|ms-vscode-remote|0.128.0
Remote - SSH: Editing Configuration Files|ms-vscode-remote.remote-ssh-edit|ms-vscode-remote|0.87.0
WSL|ms-vscode-remote.remote-wsl|ms-vscode-remote|0.104.3
Remote Development|ms-vscode-remote.vscode-remote-extensionpack|ms-vscode-remote|0.26.0
PowerShell|ms-vscode.powershell|ms-vscode|2026.1.2
Remote Explorer|ms-vscode.remote-explorer|ms-vscode|0.5.0
Remote - Tunnels|ms-vscode.remote-server|ms-vscode|1.5.3
indent-rainbow|oderwat.indent-rainbow|oderwat|8.3.1
Codex – OpenAI’s coding agent|openai.chatgpt|openai|26.5903.71938
Material Icon Theme|pkief.material-icon-theme|PKief|5.38.1
CSS Peek|pranaygp.vscode-css-peek|pranaygp|4.4.3
Live Server|ritwickdey.liveserver|ritwickdey|5.7.10
Rust (deprecated)|rust-lang.rust|rust-lang|0.7.9
Code Spell Checker|streetsidesoftware.code-spell-checker|streetsidesoftware|4.7.3
Tabnine AI|tabnine.tabnine-vscode|TabNine|3.335.0
Tabnine for Enterprise|tabnine.tabnine-vscode-self-hosted-updater|TabNine|0.4.5
Sort lines|tyriar.sort-lines|Tyriar|1.12.0
Import Cost|wix.vscode-import-cost|wix|3.3.0
ChatGPT AI|yalehuang.chatgpt-ai|YaleHuang|0.7.12
Surround|yatki.vscode-surround|yatki|1.5.0

A/B Experiments

```
vsliv368cf:30146710
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
b6b4d950:31327385
envsactivate1:31551504
cloudbuttont:31379625
3efgi100_wstrepl:31403338
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
ddid_c:31478207
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_t_632:31543129
748c7209:31512887
32d76977:31512328
ha629193:31508444
a1ije391_t:31540920
jbcp_cls_pctr_t:31531130
cp_intellij_t_nes:31548657
jf4hg949:31526829
ahp-both-windows:31556933
ihg5j128:31534457
9gg7f176:31542112
enable_editor_pane_layout:31569726
allow-none:31555437
ac562147:31564510
c7c27ce7:31554789
1h923230:31564177
0dg73464:31554319
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
a1hcc538:31559322
0c1h4866:31566224
vrbsty_tr:31561058
session-mark-done:31558131
5b8j3302:31564601
mangle-name-control:31572633
intellij_nes_preview_t:31580086
multiv2:31574985
2bfb8b39:31576696

```