Conditional Call Forwarding not working on iPhone6

I'm also having the same problem. I get an error. "Error performing request. Unknown error". Then I get a host of other errors, such as Setting Activation failed (voice maill call forwarding on all calls). This repeat several times with different types (data/fax/sms/sync data/async data/packet access/ipad access) It's definitely related to iPhone 6. If I do it on my work iPhone 5, it works fine.

I also have the same error. I was looking on the Google voice forums and someone there said the the CCF settings are stores on the SIM and it looks like the iPhone 6 just isn't writing them to the SIM or something. He said he put his new iPhone 6 SIM into his iPhone 5, entered the CCF code (**004*...etc) into the iPhone 5, and then moved the SIM back to his iPhone 6 and it worked: https://productforums.google.com/forum/#!topic/voice/XJt1i0rlm7A . So it seems like it may be an either iPhone 6 bug or an iOS 8 bug.

Me Too. ATT user.

There is a different set of "Star codes" that does seem to work.. See below - a link to the source is provided below the inserted chart.

The codes are **61.... for CF on No Answer, **62 on Not Available, and **67 on busy.

With these codes I was able to re-establish the needed forwarding for my google voicemail.. Now if only Google Voice would do a better job transcribing!

Let me know if that works for you. Best/jim

Entire chart of these codes available at:

https://www.att.com/esupport/ref/showarticle.jsp?appId=mycsp&sid=KB25569