On my Galaxy S5 (Android version 6.0.1), I can't seem to begin a new SMS conversation on any app. I can text in existing threads just fine, but as soon as I try to send a message to a number I don't have an existing thread for, my app crashes or gives me an error. I've also been seeing occasional "Messages has stopped working" errors popping up, which I believe is happening when a new thread would be created by an incoming message.
The built-in messages app crashes when I try to send the message, the Facebook Messenger app crashes as soon as I enter in the number and try to move on to typing a message, and the "Google Messages" app tells me it has "failed to create new conversation" when I move on to type the message.
This is clearly not a problem with any one app. I've tried clearing caches, deleting old message threads to make room, and downloading an extra app, and I keep seeing the same issue.
What could be causing this, and how can I fix it?