For 2 days I was now struggling with this response and my sanity strained to the end. I've read all the treads regarding this, changing and nothing worked. Like in really, I was close to tears as I cannot fix it and I do not know how. Remember I am totally new to this and most of it is like a foreign language. But then one admin advise me to ask for help. Eventually I figured out I have to contact Dreamhost and ask for help. The fault was on the server end and they rectified it.
So Guys if you tried everything and it does not work, try that. Hopefully it will save you a lot of stress.