I just installed the most recent version of K2, I'm using Joomla 1.7.2 (but also had this issue when using Joomla 1.7.0

Whenever I go to the media manager in K2 I get a pop up that says "Invalid Backend Response. Data is not JSON"

Have I missed something? or not enabled something?


I saw someone had the same issue but the responses were not in English. If anyone can help out I would greatly appreciate it. I'm new to K2.