Railo and "Server is currently unavailable or down for maintenance"
I recently got a "Server is currently unavailable or down for maintenance" every time that I tried to pull up a web page on my local computer. It took me a while to figure out what had happened.
As it turned out, I had installed Railo on my computer and then deleted it (deciding to run the express version instead). Apparently, I must have missed an uninstaller or something.