ESS / MSS not working

Dear Gurus,

We have EP 7 and our ESS / MSS was working fine but yesterday all of a sudden everything stopped workiing. I have noticed that all the JCo have greyed out and the status is show as "Unknown". I tried few things and even restored previous backup but still the same. I suspect something went wrong in the backend ECC system? Can anyone advice what should I look at?

Best Regards,