When I enter a message, I can see it in the entry box. Then when I press enter to send it to the chat, it disappears. I can't tell whether others see it, because I can't see anyone else chatting. I know people are, because the chat highlights the way it usually does, I just can't see it.
I downloaded from the MIRC website download link. I even tried uninstalling/reinstalling, to no avail.