I got a cell line from a friend. The cells grew well in the medium he provided. But when I changed the medium, the cells started dying. I had already used the same lot of medium and FBS for culturing the same cell line earlier without any problems until I lost my cell line due to contamination. The lot of cell line that I got from my friend did not grew in my medium.

Then probably your media is not right. Check the components in your media and verify with your friend about the media.