What is the reason for the black-and-white screen of Yancheng page of my Huawei mobile phone?

Network problems. Huawei mobile phone downloaded my Yancheng page black and white screen because of network problems. There is no network, the network is not good, the application data cannot be loaded, and a black and white screen will be displayed. You can switch to a stable network and try again. "My Yancheng" App is an urban life service platform carefully built by the municipal party committee and municipal government, integrating government services, public services and life services, creating a unified entrance for urban services and providing citizens with "one-stop" government services and convenience services.