Hello,
This is an old post, but I just found this problem on mac, and to solve it you have to go to the folder or the file and check that you have the "Read and Write" rights. Even if I was administrator, it didn't work because I had to install it on another account... To do this, right click + read information and you will find it at the bottom. Check that your lock is open.
Théophile Demarcq