Cannot Modify Import settings

Hello everyone, I'm having a weird issue in which I cannot modify Import settings. it doesn't matter what I'm changing or what whenever I hit apply it doesn't apply it. so when I click off the inspector I get an error messege saying changes were not apply and there are two buttons apply and revert. I hit apply but still nothing happnes.
I'm trying to import a simple png image and change her import settings and a 2d brand new project there is nothing in it but that image.
thanks in advance,

 

I'm getting the following error at the bottom whenever i try to change the import settings:
http://gyazo.com/7c73fe504ae27820e68393be543c9aaf

 

I reinstalled unity and it solved this and the gravity issues I was having