I have tried deleting all conversations with this person, moving to Safe mode, nothing works. Neither she nor I use an iPhone, we're both androids. I do hook up my phone regularly to my car, and she does to hers. Don't know if that's what's going on, if so I'd appreciate hearing a suggestion for what to reset how so I can text her again. Currently using WhatsApp since Verizon messaging is not working.
The problem fixed itself after my friend deleted a bunch of group texts from her family that had accumulated over the holidays. We're able to text again, thankfully.