I used to be able to text while having a phone conversation, now I can't. What could be the problem?
You're supposed to be able to text while you're on the phone, if I'm not mistaken. I used to do it all the time. All of a sudden, it stopped. As soon as I press send, the red exclamation point pops up and says "unable to send". How can I fix this or can I?
iPhone 4S