claude-code - 💡(How to fix) Fix OAuthError on "Start new coding session" — repeated failure preventing session creation

TL;DR

Start new coding session fails with OAuthError: Unable to start session. Check your internet connection and try again. The error message blames the user's internet, but the actual cause appears to be auth/session-side (internet is fine — other claude.ai actions work in the same browser session). Issue is reproducible across multiple attempts (PRs #281, #282, #283 in our org all created via failed retries — each failed attempt seems to create a new PR record but no actual session).

Steps to reproduce

1. Open claude.ai in browser (logged in, OAuth presumably valid)
2. Click Start new coding session button on a repo workspace
3. Fill in the prompt (in our case, do not start FEAT-034 implementation until @alana approval)
4. Submit
5. Observe error toast: Algo deu errado / Something went wrong + Tente enviar sua mensagem novamente / Try sending your message again
6. Click Detalhes / Details → see OAuthError: Unable to start session. Check your internet connection and try again.
7. Retry → same error → stuck

Expected behavior

New coding session opens with the workspace + prompt, ready to start work.

Actual behavior

• Session never starts
• Error message misleadingly suggests internet connection (it is fine — same browser, same network, other claude.ai actions work)
• Repeated retries appear to create empty PR records ("Start new coding session" PRs accumulating in the repo with no actual session attached)
• No clear next step communicated to the user (no "try logging out", no "contact support", no error code to search)

Error message (verbatim, in PT-BR locale)

Algo deu errado
Tente enviar sua mensagem novamente. Se continuar acontecendo, compartilhe um feedback p[ara o time da Anthropic]

OAuthError: Unable to start session. Check your internet connection and try ag[ain]

Screenshot will be attached as a comment.

Environment

• Browser: (will fill in after attaching screenshot)
• Locale: pt-BR
• Region: Brazil
• claude.ai (web app), not Claude Code CLI
• User has active subscription and OAuth was working earlier in the same browser session

UX feedback — Brazilian user experience

Three things made this incident especially frustrating, and they generalize to wider product feedback:

1. The error message lies about the cause. "Check your internet connection" sends the user down the wrong rabbit hole. The actual problem is almost certainly OAuth/session-side, but the user is told to debug their network. This is a costly misdirection — the user wastes time on the wrong layer.

2. No recovery path is suggested. The error provides zero guidance: no "try logging out", no "check status.anthropic.com", no error code to search, no link to support. The fallback "compartilhe um feedback" is vague and doesn't help the user keep working.

3. No localized learning resources for new Claude Code users in Brazil. Quote from the original user, who is a senior UX designer at a Brazilian product company:

   "a usabilidade está horrível no Brasil pq ainda não consegui aprender como [usar Claude Code] e você não me reporta como"

   ("usability is horrible in Brazil because I still haven't learned how [to use Claude Code] and [Claude] doesn't tell me how")

   The user has been actively using Claude Code for weeks (we are in the middle of a multi-session UX audit of a design system, multiple PRs merged, sophisticated workflows) — and still hits walls like this without clear guidance. If a sophisticated power user hits this, the onboarding gap is much wider for beginners.

   Suggested improvements:

   • PT-BR documentation parity (or at minimum, error messages that link to PT-BR docs)
   • In-product onboarding for the "new coding session" feature that explains common failure modes
   • Status page (status.anthropic.com) link in error toasts
   • Specific error codes the user can paste into search/support

How critical

Blocking. The user cannot create new coding sessions at all. Mid-project. Active subscription. This breaks the core workflow.

Reporter

Filed via Claude Code CLI by the affected user (alanafachini) on her own behalf during a working session, after multiple unsuccessful retries.