Thanks — I can help. This looks like an error report (Facebook login failing). I’ve summarized what you’ve provided for the support team and included troubleshooting steps and next actions.
Summary (from your report)
- SDK Details: MetaMask Embedded Wallets (Web3Auth)
- SDK Version: @web3auth/modal-react-hooks ^9.7.0
- Platform: Hosted wallet (Web / React — inferred)
- Network: SAPPHIRE_MAINNET
- Verifier: web3auth-facebook-sapphire (default)
- Error: “The app you are trying to use does not exist or is unavailable” when logging in with Facebook
- Started: Around 2026-01-18
- Other providers (Google, Apple, Twitter) work fine
Why this usually happens
- This message is commonly returned from Facebook/OAuth when the Facebook App ID used by the verifier is not available (app deleted, disabled, or still in development mode), or when redirect / OAuth settings are mismatched or blocked. Since other providers work, it likely indicates an issue specifically with the Facebook app/verifier (revoked credentials, app settings changed, or a Facebook-side policy change).
Immediate troubleshooting steps you can try
- Check Web3Auth / verifier status
- If you are using a hosted/default verifier (web3auth-facebook-sapphire), the Facebook app backing that verifier may have been changed or disabled. Check Web3Auth status/announcements and the hosted-wallet status pages (Web3Auth status page and MetaMask/Builder announcements). If you don’t find anything public, try contacting Web3Auth support.
- Reproduce and capture logs
- Open DevTools → Network and reproduce the login flow. Look for the request/response to Facebook’s OAuth endpoint (facebook.com or graph.facebook.com) and note the exact error payload.
- Capture browser console output and a screenshot of the error dialog/console/network response.
- Try in incognito and another browser to rule out caching/extensions
- If possible, test with a custom Facebook app/verifier
- Create your own Facebook App and configure a custom Web3Auth verifier (if you can) to verify whether the hosted verifier is the root cause. The Builder Hub / Web3Auth docs explain custom verifiers.
- Check redirect URIs & OAuth settings (if you control the FB app)
- Ensure the app is Live (not in dev mode), valid OAuth redirect URIs are configured, and the app has required permissions.
What I recommend you send next (optional, only if you’re ok sharing)
- Browser console screenshot and Network tab capture showing the failing request/response to Facebook
- Code snippets for Web3Auth initialization and login (initialization of modal + login call) if you used any custom config
Links & resources
- MetaMask docs: https://docs.metamask.io
- MetaMask Builder Hub (for custom verifier guidance / integrations): https://builder.metamask.io
- Web3Auth docs (for Facebook verifier specifics and custom verifier setup): Introduction | Documentation | Web3Auth
If you’d like, I can escalate this to the support team — I’ll include the summary above. If you can attach a console/network screenshot or the init/login snippet, that will speed up diagnosis. Do you want me to escalate now, or will you try the troubleshooting steps and share logs?
Note: This response was generated by an AI bot and may require further verification. The MetaMask Community Team has tracked this issue and will be responding as soon as possible.
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