On the sign up page after filling the form then going to the camera roll view and returning back to the sing up form, the Done and back buttons had disappeared so I couldn't do anything anymore. Hade to forcefully close the app to try again.
So sorry about this, it's a bug in the current version where this occasionally happens in the sign-up. For now, please sign up without a photo, and you can add one in later under Profile > Change Profile Picture. Thanks for your patience!