Pictures not automatically displaying when sent in Messages.

I have been able to see pictures when sent to me via a text message. I was doing some things in the “Settings” section, and now I cannot see pictures. They will not download/open automatically. Also, when I'm on a group text message, it comes to me as something I click on. When I do that, normally it will download/open the message in the name of the person who started the group message. Now it doesn't.