Galaxy S4. Got this error message for sending mms randomly after no issues since I got the phone (approx 1.5 years now) It worked the day before. Data is on, APN checks out (won't let me edit that anyways) and the sms/mms are all the original default. Everything is updated on my phone. Android 5.0.1 I read many of the other similar forum posts - didn't seem to be an answer that worked for others and seems frustrating that it happens randomly by no fault of the user.