Go to the registry editor (Win+R; regedit)

go to HKEY_CURRENT_USER -> Software -> Microsoft ->Office -> 16.0 ->Common -> Identity

Inside "Identity", create a new REG_DWORD value called "EnableADAL" and leave the value at 0

Restart the PC and try again to login from Office 2016.


https://answers.microsoft.com/en-us/msoffice/forum/msoffice_account-mso_win10-mso_o365b/unable-to-sign-in-to-office-2016-desktop-apps-sign/b32738c8-1b17-43d1-839b-cb97c8ae3c29