the operation could not be completed com.apple.mobilephone error 1035

I had this problem on an iPhone6S when trying to reset my voicemail on T-Mobile. I was able to change my voicemail by following T-Mobile's instruction on how to reset my voicemail:

Change your greeting

1. Press and hold the 1 on your device's dialpad to call and connect to your voicemail.
2. Press the * key to access the main menu.
3. Press 3 to access the Greeting menu.
4. Press 2 to record a new greeting. If you're replacing an existing greeting, the existing recording plays first.
5. When prompted, record your greeting. Press the # key when you're done recording.
6. Press 1 to set your recording as your voicemail greeting.

See: https://support.t-mobile.com/docs/DOC-1171

I had the same error. Apparently, the voicemail feature was not activated when you purchased your phone. After several calls to AT&T i reached someone in tech support who turned on the feature. Call your carrier from a different phone, ask them to turn the feature on, then go to voicemail - you will see a different voicemail set-up screen and it will prompt you to record a message. After I recorded mine, I got a screen that said "Setting up voicemail." after about 10 minutes of waiting for that to complete, I called the new phone from a land line and let it ring until voice mail picked up. When it did, the screen on the phone went to the normal voicemail screen and all is working again. Hope this might help.

I realize this might be a moot point but for anyone visiting this thread now, I just encountered this problem with my new iPhone 7 plus. I have Verizon. The solution that worked for me was to set up the voicemail through Verizon by dialing *86.

I switched iPhone 6s from AT&T to Verizon. The visual voicemail on iPhone phone app did not work anymore. All methods on Google search as of 12/24/2017 did not fix it. It turned out that Verizon did not turn on visual voicemail for my iPhone. A visit to Verizon store fixed it.

Same error message, same attempted operation. iPhone 6, iOS 10.0.1

Generally error 1035 is indicative of a failed attempt to modify the

stock iOS install. Be advised such hacks may render your

iPhone permanently disabled, and un-restoreable to stock iOS.

I have the same problem with an iPhone 6 and Verizon. Anyone with any tips?

I think that you just need to follow whatever instructions Verizon gives for re-setting your voicemaiL. I have been thinking about this problem and I suspect that the carriers have some setting that are conflicting with the native iPhone voicemail setup. Since we can just hold 1 on T-Mobile and get our voicemail there seems to be some custom code at work here.

I went round and round with Apple and AT&T about this error after getting a new iPhone 7. Finally this morning I reset my phone to factory settings (erase all content and settings) and instantly my visual voicemail shows up with no errors.

Things we tried that had no effect:
1. A New SIM from AT&T

2. Resetting Network Settings multiple times

3. AT&T completely resetting my voicemail multiple times.

4. AT&T changing the pre-paid plan I was on to reset my entire account.

5. Eliminating my voicemail password.

6. Trying to change the voicemail password from the phone multiple times.

7. Trying to change the outgoing greeting from the phone caused the 1035 error. But this was all a symptom of my visual voicemail not working.

Erro1035

The voice mail

I can't seem to set up or play my voicemails for some reason???

Voicemail is a function provided by your wireless provider.

Contact them for assistance.