@krsna.Booti , @manon1165 , sorry for the late reply. I had the same problem 10 minutes ago and found the fix : you should in the “Template:” field you should specify the actual name of the directory where the parent theme resides not the parent theme’s name. This means that it doesn’t matter if in the stylesheet of your parent theme “Theme Name:” is “Twenty Eleven” for example, in the child theme you should say “Template: twentyeleven” because that is where the template files reside.
Hope this is helpful,
Cheers!