Network failure. Chinese patents refer to new technical solutions proposed for products, methods or their improvements. If the digital certificate download prompt does not make a download request, it is the cause of a network failure. You can refresh and re-enter. A digital certificate refers to an electronic document issued by a CA organization. It is a string of numbers that can indicate the identity of a network user. It provides a way to verify the identity of a network user on a computer network. Therefore, a digital certificate is also called a digital identity.