Why can't I receive texts from this person on Driod Turbo?

[AC Question]

A friend of mine can receive my texts, but I can't receive hers. I know I can get texts because when I text my sister she replies and I get her message and vice versa. I don't know what happened, as far as I know, I didn't press any buttons that could have blocked the number.

 

[Rukbat]

If she's using an iPhone, it's possible that her phone is set to send you iMessages, not SMS, which you won't get. (That's even more likely if you used to use an iPhone.) Tell her to send you a text and to make sure it's marked SMS. If that works, her phone should send you SMS messages from now on. (Otherwise, you may have blocked her - check your SMS app settings to see.)