As an unhappy Vodafone “customer”, I sometimes get this error when sending an SMS. Which is a pain in the middle of solving a water crisis in an arid landscape environment. The only explanation I came across was Italian, and tech support blamed Android.
Just delete the message thread. No idea why this works. But after deleting the message thread where I got the original error, I was able to send text messages again.
To get to the studio which I work in, I have to walk down a lane way. I came back one night to catch up on some work and I couldnt see my way in the dark night. Luckily I remembered that I downloaded this phone application that uses the cameras flash as a flash light. It does the trick perfectly. The torch is much brighter than I expected.
I recommend downloading this app for Android phones. You never know when you might need it. It deserves a five star rating.