I can not sign up for the application over the phone

When you click on “Sign Up” and fill in the fields, they are all marked as correct, a red letter “C” appears above the first field and registration is not completed. What could be happening?

What application are you talking about?

Ionic View on a phone with Android.

It could be with the current Ionic Pro migration happening that signup for the old version was disabled. Unfortunately there is no new version for Android yet: https://ionic.zendesk.com/hc/en-us/articles/115012098448-Can-t-use-or-log-into-Ionic-View (see last sentence)