The ‘gpt-5.6-sol’ model requires a newer version of Codex. Please upgrade to the latest app or CLI and try again.
=> Despite being on the latest version.
Trying to check if it works under Pre-Release.
You are welcome to discuss Codex issues on the forum, however the official place to report and track them is the GitHub issue tracker for OpenAI Codex.
I had ChatGPT look for the closest related issue and it identified:
If that issue matches your problem, consider adding a 
reaction on the GitHub issue page itself, not just on the forum topic, as reactions on GitHub help the developers gauge impact and prioritize work.
If it is not the same issue, try searching the existing GitHub issues for a closer match. If you cannot find one, then open a new issue with as much detail as possible.
Thanks for the info. I will try. Considering you had the “bug” flag here; I assumed 
No worries, that is why we are here.
Hope you reach a successful resolution.
Hey @Mb,
Getting an upgrade message when you’re already on the latest version is confusing. Thanks @EricGT for sharing a similar report.
If this is still happening, check for any Codex updates released since your post, fully restart the app or editor, and try a new session.
Could you confirm whether you’re still seeing the upgrade-required message, or whether Codex is now working normally?
~ Ankit
I updated the extension manually, and that worked.
However, there is still an issue with VSCodium: the extension marketplace does not seem to provide the latest Codex updates. I had to manually install versions 26.930.31730 and 26.51002.51308 to get access to GPT-6.1 Sol. I’m not sure whether this is intentional, but it was working in the desktop app.
There is also a minor HTML rendering bug in LibreWolf. I hope that helps 
Hey @Mb,
Thanks for confirming that manually updating the extension cleared the upgrade-required error, and for sharing the additional details.
VSCodium uses Open VSX as its default extension registry, which differs from VS Code’s marketplace. That may explain the update difference you saw, although I can’t confirm the specific cause or whether the delay was intentional.
For the remaining marketplace-update and LibreWolf rendering issues, please open separate new thread with the affected editor/browser versions and steps to reproduce. You can link back to the screenshots already shared here, or contact OpenAI Support if private diagnostics are needed.
~ Ankit