Rails服务器的问题

[进击的愤怒]

我的Rails服务器总有问题:
We're sorry, but something went wrong.

We've been notified about this issue and we'll take a look at it shortly.
不管我在http://localhost:3000/后面写什么都是说这。我用gem install mongrel -y和gem install mongrel_service -y下了mongrel，在3000和3001下也是这样。怎么办呢？