I can't enable/disable MMS or GROUP messaging on my iPhone 5s anymore! I have recently downloaded the iOS 8.0.1, not sure if that's why! The option is no longer in the settings.
The camera is greyed out in the messages app, next to the typing window. When I try to send a picture message from selecting the pic from my photos, I get a message saying "MMS Messaging needs to be enabled to send this message."
iPhone 5s, iOS 8