Problem with launching Vagrant

[Zeus_Dev]

Hello everyone,

So Im having a problem while trying to launch my vagrant image. So I go to the directory when I have my vagrant file and everything, I typed on my terminal : vagrant up as usual, and I had this error message : 

A Vagrant environment or target machine is required to run this

command. Run `vagrant init` to create a new Vagrant environment. Or,

get an ID of a target machine from `vagrant global-status` to run

this command on. A final option is to change to a directory with a

Vagrantfile and to try again.

and when I try to launch my image on virtual box it works perfectly !

So any one can help me please; Thanks :) 

[Alvaro Miranda Aguilera]

do you have a Vagrantfile on that directory? 

whats the context of the Vagrantfile?