Error #3501 occurs when your sign-in is treated as needing an enterprise/business license with no active license found for the account, or when the connection is rejected due to geographical availability restrictions (where the system throws the misleading #3501 license error instead of stating that the region is unsupported).
Could you please try the following steps:
Reset Your Cached Session & Clear Enterprise Auth Routing:
Check if AGY_ADC_AUTH (Google Cloud credentials) is set in your system environment variables; if so, unset it and restart the application.
Sign in again with your personal account: When prompted, select your personal @gmail.com account, not an Enterprise, Workspace SSO, or Google Cloud option.
If the Error Still Appears: Please reply here with:
Your Antigravity platform (Antigravity 2.0 app) exact version and OS.
Your country/region and whether you have a Google AI Pro/Ultra subscription on this account
If you encountered an error, please attach either your diagnostic logs dumped in a .txt file (from Help > Toggle Developer Tools > Console or View > Output > Antigravity Language Server) or an error screenshot.