Codex Paris workshop promo applies discount but checkout fails

What happened?

A promo code shared for the Codex workshop in Paris appears to be accepted by the Codex promo flow, but the final checkout cannot be completed.

Context: the code was shared for this Paris event: Build Your Webshop with Mollie & Codex, hosted by Boris, Mollie Payments, and Katia Gil Guzman. Boris / @borvibe is listed as host and Codex ambassador in Paris: https://x.com/borvibe

The promo flow says 2,500 credits will be applied when creating a Codex workspace. On checkout, the discount is visible and the amount due is $0.00, but clicking purchase fails with the generic error:

Un problème est survenu. Veuillez réessayer.

What I tried

• Logged out and back into ChatGPT.
• Logged out and back into the Codex app.
• Tried multiple credit cards.
• Tried Apple Pay.
• Reopened the promo link and retried the checkout.
• Shut off my VPN and retried checkout.

Same result each time. The promotion appears to apply, but checkout still fails.

What can I do?

Could someone confirm whether this promo code / checkout flow is expected to work, and what I should do next to activate the workshop credits?

I can provide the exact promo code or account details privately if needed. I am not posting them publicly here.

Related public reports

I found a related Reddit thread where another OpenAI billing/promo checkout flow failed after users tried logout/login, country check, and different cards. In that thread, one user reports support had to cancel/purge old billing data before purchase worked, and another comment mentions VPN-related payment failure. This may point to a billing/promo account-state issue rather than a card-specific issue:

https://www.reddit.com/r/codex/comments/1tjfxcf/comment/or31or9/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

https://www.reddit.com/r/OpenAI/comments/1nnjcs8/cant_upgrade_from_plus_pro_there_was_a_problem/

Local evidence checked

I checked local ChatGPT/Codex app logs and browser state for a safe, publishable error log. I did not find a useful checkout-specific log that can be shared publicly. Browser storage contains sensitive cookies/session data, so I am not attaching raw local files here. The redacted screenshots below are the safe public evidence.

Evidence

Redacted screenshots attached below. Personal data, payment details, billing address, checkout session URL, and raw promo URL are hidden.

Promo modal:

!Redacted promo modal

Checkout error:

!Redacted checkout error