Can someone help with an Initialization Error?

I am fairly new to Mac. I have been trying to install the software for "My Uno Cards". I have downloaded the Mac Download however I get an error message when I try to install it.

Initialization Error….
Could not create the application support directory 'Macintosh HD:Library:Application Support:My UNO Cards:'.

I have installed the same downloaded software on a Macbook Pro and it works but I cannot get it to work on my MacBook Air (OS X 10.8.4)
Any suggestions on what I can do?:(