This is due to a program administrator marking this user 'inactive' with the User Administration tool. They are a valid, active user on their Intranet but were flagged as 'inactive' as if they've left the company. This may happen if someone leaves the company and then returns some time later. Verify the user is active within the User Administration on the company page and have them retry. Please Submit a request if this behavior continues.
If the user is not inactive there could be a partially created account which is utilizing the email & not allowing access to user attempting to login using the same email. If both the previous issue are not the cause of the login failure and your company uses SSO to login, it could be that the unique ID which authorizes you into access does not match. Please request your company's IT provider to Submit a request and send along your foreign ID.