As we’ve noted in several of our previous Dev Updates, **we are now turning on Email Authentication for SDK logins**. You may receive a prompt asking you to check your registered email and enter a code when logging into the SDK after certain changes.
*If you are using an up-to-date SDK, then you have nothing to worry about, and no action is required.* Thank you for keeping your SDK up to date! Make sure you keep it updated via the VCC (<https://vcc.docs.vrchat.com/>).
**If your SDK is very out of date, you will need to update your SDK, or you will need to add 2FA to your account.** SDKs more than about a year or so old do not support the email authentication method properly and will fail.
**If your SDK is VERY VERY out of date (like… four years or more), you will be unable to login.** In addition, since your SDK is so old, you won’t be able to use 2FA. You must update your SDK to work around this issue.
Per our analytics, we expect this to affect *very few users.*
Please see this Dev Update for more information (linked to relevant section): https://ask.vrchat.com/t/developer-update-30-march-2023/17186#sdk-email-authentication-soon-1