Thanks for getting back to me. I was working on the problem this morning. That’s why you didn’t see the error message.
What I did figure out is, for some reason, the exp_sites table was completely empty in the database. I don’t know why that would have happened. Fortunately, I had a back up from a long time ago and I was able to insert the data and now it’s working fine. How it disappeared in the first place, I don’t know. This is site is on Super Green Hosting which is probably a part of the problem.
Thanks for your reply.