Several users are getting the “com.apple.mobilephone error 1035” error on their visual voicemail whenever they try updating or setting up their visual voicemail greetings. Visual voicemail lets you view your voicemail message that you receive. Voicemail greeting is the message that callers will hear before they are offered the opportunity to leave you a message. However, this error will prevent users from setting up their greetings. The full error message will be “The operation couldn’t be completed (com.apple.mobilephone error 1035)“.
-Hey! Sorry I missed your call. If you’re a telemarketer, then I’m definitely not sorry. If you’re not a telemarketer, then I’ll return your call as soon as possible.

Open your Phone app. Tap Voicemail. Select Greeting. By default, your voicemail will be setup with your carrier's generic greeting. To record a custom greeting, select Custom. Tap Record to begin recording your voicemail greeting. When you finish recording, tap Stop. To make sure you're happy with your new greeting, tap Play.
I called customer support. They were not able to fix it and made it worse. Now it rings once instead of three times. They put in a service request and said it would be 1-3 days. Now they say 3 to 5 business days. I don't understand how something so simple could be such a major problem. I just wanted them to change the number of rings to at least 7. Disconnected the 1st of the junction boxes at top of door. Phone line rings after doing this so proves problem is in the home. I then ran a new wire pair to the NTE5, problem then came back, even with the pull out isolation port or whatever it’s called. Then wired direct to the back plate if that’s the correct term, phone starts ringing again.