API not working!

Hi, this is quite an urgent matter. I am trying to access the api but having this message show up, "status":{"code":7,"text":"Authentication Failed - You do not have permissions to access the service","error":"Login Failed"},"data":"Authentication Failed - You do not have permissions to access the service","error":"".

i am using api v1

I am using this client:

ShiftPlanning PHP SDK
Version: 1.0
Date: 11/01/2010

everything was working perfectly until 1.5 days ago

so how is it possible that all of a sudden things are not working.. we did not change anything from our end