A
Agree sounds like a MMSYour messaging (text) app is looking for a text or, more likely, an MMS, that it was told was there, but it expired. There's nothing you can do about it. Look to see what texts you have that you haven't read and, if it still persists, open the text all in Settings > Apps & notifications, and clear cache. (Don't clear data, or you'll lose all your texts.)