I have just created a child theme for Twentyeleven, which worked ok, it made the site look weird.
But then i made a child theme for Under the Infuence (the theme i had before), installed and activated it, but then it said the parent theme wasn't installed. Then i switch back to twentyeleven, but then it said the same; parent theme not installed.
The themes are working fine even though it says that they aren't installed.
My child theme for Twentyeleven:
Theme Name: Twentyeleven Child
Description: Child for Twentyeleven
Author: Martin Sundskarð