"There are several companies associated with the domain." error pops up
If several companies exist with the same domain (Admin Area -> Domains), then newly registered users must select the company to which they wish to be assigned to.However, when using external SSO providers (Google, Microsoft, OpenID), we cannot show the user a dialog to select their company when creating the account. This results in the error message "There are several companies associated with the domain." appearing on the 1st login.
As an administrator, you should contact our support so together we can find out if the 2nd company is a duplicate or real company.