I don\'t know what I did. I think I updated my Ruby on Rails. After updating it, I always get error when running $rails server.
output is
ruby-1.9.
I too faced the issue it all because of ruby instances are not properly terminated.We can terminate processes running in the background by pids.
lsof -wni tcp:3000
It displays all running pids of ruby.and terminate that pids.
kill -9 PID
Or use
killall ruby