A customer and I were trying to re-run the SharePoint hybrid picker, and we kept getting a "Wrong tenant credential" error. We knew the account had global admin rights in the tenant. After digging through some old emails we realized that they Hybrid picker does not support multi-factor authentication (MFA) enabled admin accounts. To work around this, have someone temporarily disable MFA for the GA account/credentials that will be used by the wizard/picker.
https://github.com/MicrosoftDocs/OfficeDocs-SharePoint/issues/101
https://sharepoint.uservoice.com/forums/282887-sharepoint-hybrid-or-migration-to-office365/suggestions/34461736-enable-mfa-for-sharepoint-hybrid-config-wizard
WrongTenantCredential
