Call forwarding error

[me75006]

G3, TMO, Lollipop.

When I try to set up call forwarding, All Calls, either by manual input of number, or selecting it from my contacts, I get an error message:
Title -"Call Settings Error"
'Unexpected response from network'

Same thing for the other types of forwarding.

 

[me75006]

Per Customer Sevice:
Prepaid Plans, can only be to TMO voicemail.

Postpaid Plans, can be forwarded to any number

and, I went prepaid previously.

 

[simony]

I got a similar error from AT&T (network/sim error).. Contact live chat agent and somehow he's able to do the conditional call forwarding for me..