Some time ago, I created a chatroom for the Reflections language. Now, I can't find it, and if I click the link on the Reflections page, it's not found. Has it been deleted? Why?
Yes, inactive rooms get deleted automatically after a while:
Rooms will exist indefinitely, so long as there is at least one person actively talking in the room. A room is considered worth retaining if it has more than 15 messages by at least 2 users.
— Source: Chat FAQ
I've undeleted the room for you. If you can get a bit more activity in there, you shouldn't have to worry about it being deleted again. However, inactive rooms will still freeze after 14 days of inactivity, which will prevent further messages. Should that happen and you need the room again, feel free to ping one us moderators in The Nineteenth Byte and we'll unfreeze it for you.