Hello fellow Mac users and experts. like many others i downloaded the new OS X, i have an older external harddrive that I used with my former Windows Pc, on Mavericks i did some "magic" to make my new Mac working together with my External harddrive. But here is the problem, after i installed Yosemite, i can no longer transfer files from the mac to the external harddrive. after searching the web and this forum, i haven't been abel to find a solution. Can any one help me ?