"App not verified" or "App blocked"
Your Google Workspace admin has restricted third-party apps. Ask them to allowlist omb.cloud in Workspace Admin → API Controls. Then reconnect.
"Insufficient permissions"
You connected with a scope but later the integration needs another. Disconnect and reconnect to refresh the consent screen.
Token expired
Periodically Google revokes tokens (password change, admin action, dormancy). The integration shows a yellow warning. Click "Reconnect" — takes 10 seconds.
Calendar shows no availability
Either your working hours are misconfigured (Settings → Calendar) or every slot is blocked by existing events. The booking page respects "free" slots only.
Sending from Gmail fails
If you have 2FA + app-passwords mode, OAuth still works (recommended). If you're trying to send through SMTP with username/password, switch to OAuth — Google has deprecated SMTP basic auth for most accounts.