In a chat room in Area 51 that has been frozen, such as StackOverflow en español, there is a little problem with the message that the room has been frozen by inactivity:
Believe it or not, the message is there. You will need very good eyes to see it, and it just looks like a blank spot, and people will wonder what is happening. The only way for a mere mortal to see it is to select it:
Can the color of this text be changed, so we can see it?