[Shamburglar]

Don’t be a jerk. I had the very same problem last night when I was installing a brand new version of Final Cut Studio on my machine. I only have one account and was logged in with administrator priviliges. This error is a legitimate problem and I called Apple Care. The solution was easy.

I had to trash a file called Final Cut Studio ID located in the pro apps support folder in the library… then load final cut and reenter the Final Cut Studio serial number and all worked fine.