Why does my reply to a group text show as not delivered?

[iMore Question]

I have an iPhone 4S

 

[Rob Phillips]

Welcome to iMore! Are you still experiencing issues? It seems that there were a lot of people having issues which seem to have dissipated.

 

[Ledsteplin]

I still get those some with sending photos. It's hit or miss. I hope it's gone in 9.2.