The other day I added a new controller, and any time I browsed to anything in that controller, the web browser displayed a status 500 Internal Server Error. There was no debug screen. I looked in the development log file, and this showed up:
/!\ FAILSAFE /!\ Mon Dec 22 14:13:51 -0500 2008
Status: 500 Internal Server Error
wrong number of arguments (1 for 0)
with a full call stack. After digging around Rails code and looking around on the Internet, I finally figured out what the problem is. You can't have a method called send in a controller. After I renamed the send method to something else, everything worked.