If a UserProvider fails to setup, the contentserver used to run nevertheless, which led to accidental deactivation of users. Now, the contentserver does not go online any longer if a UserProvider fails to setup.

There is a flag cap.server.userproviders[n].mandatory (default: true), which you can set to false in order to achieve backward compatibility. However, we do not actually see a usecase for the old behaviour, and we recommend to leave the flag at its default.

(CMS-25871)