This issue is still happening on my iPhone 5s. I have deleted the contact, deleted the message thread, renamed the contact, sent a message using only the area code and number, sent a message using 1+(area code) and number, reset my network settings....it's still happening!
It appears this issue has been finally resolved.
I just happened to call Sprint regarding my first bill and they asked me if I had any other questions or concerns and I brought that issue up. She did say there were known messaging issues with the Iphone 6, asked me to turn my phone off, she reset my messaging, turn phone on, and now I can text that person I was having an issue with!
Still does not work on my iphone 6+ I am at a loss here. I tried all the things I found around the net.
Deleting everything with that number in it, and the error message. Delete the contact, reset network settings, turning off imessage sms etc, restarting, try to text before turning settings on, after turning settings on, add the contact all using the 10 digit code. Same damn error!!
You would think by now they would fix this. I am at a loss.
OMG!!! It worked... I deleted the contact, deleted the texts and any threads the number was involved in. Then I texted the number again with the area code and it went through. Then I created the contact again. Great success! Thank the gods for this thread!
so I dad this same problem. at 1st it was only doing this with my stepsons number. and to be honset i couldnt figure it out and thought his mom got in his phone and blocked my number just to be mean and start trouble. that was all i could think of cause it was just his number, and my husband had no problem texting his son. and even got replies. so i guess anyone could see why i thought what i thought. but anyway 9 months later out of the blue another contact started doing this. never had any problem with her number befor just flat out of the blue. so this is how i finally fixed it to fix the problem on sending text to my friend and to come to find out it actully fixed the problem period. even my stepson number was fixed. i open the icon were you go to recieve and send text message. then puch the blackberry icon button thats right beside the send button. scroll down to options and select. then select inbox settings. make sure there is a check in the little square beside SMS And MMS if not check it. from there exit back out and try sending a text message to number that been having the problem. it should work for there but if not return back using same way before but after selecting options select General Options. then scoll down until you come to Show Recent Contacts When Composing Email. change that to no. back out and also drop back in to inbox settings to double check that the little box still has check in it. that will fix the problem i Promise!