I was adding new chat capture expressions to handle characters following whoever issued the command (follow, using a portal, life stone recall, etc.) I was condensing them down to a single rule rather than one for each toon who could possibly issue the command.
I opened the meta in notepad, but I wasn't sure how to even spot an error since the format is so outside my experience. I looked at the rule I was editing right before the corruption, but maybe I can revisit that (especially if it means I don't have to rebuild the meta.) Good to know that the beginning also needs to be edited as well though. I never would have picked that up on my own.