unlocked HTC One on ATT isssues

[Wineman01]

Hi all,
I purchased an HTC One in Hong Kong and am currently using it on ATT's network. ATT told me that I cannot use their Visual Voicemail app since it's an unlocked phone. I downloaded Google Voice and am trying to set up their Lite service so I can use VVM. When I try and change the Voicemail service settings to 'Google Voice' I get an error that 'Failed to retrieve and save current forwarding number setings.' Does anyone have any ideas?
Thanks in advance!

 

[poncewattle]

I have an unlocked Developer Edition and Visual Voice mail works just fine. I just downloaded the app from the Play Store.

 

[Philip Pearl]

Same here. I purchased an unlocked HTC One direct from HTC. I'm using it on ATT and I downloaded Visual Voicemail from the Play Store. It works as advertised.