You can sometimes fix the "your phone is not registered on a Network ... how your phone connects to your carrier's network for mobile data; if they're wrong or outdated, you may experience ...
Often, this quick fix is enough to refresh the network connectivity on your phone, allowing it to connect to cell services again. You can also attempt to select a provider manually by navigating ...
There might not be an immediatet fix — that will likely require Verizon's network resolving its issue — but there are some steps you can take to try to get your phone working again.