Can't install software on new MBP 15" retina

I'm setting up my new 15" retina MacBook Pro (mid 2015). Rather than transferring apps and data from my old MBP, I've been setting it up from scratch. But right out of the box, the new MBP has been unable to install software. Any installation or update software hangs or quits. So does Migration Assistant. My workaround has been to boot into Safe Boot Mode; then I can run installers and add software. But some of my older apps (like Adobe CS5) want to install newer updates, and they don't work well in regular or Safe Boot mode.

What can I do? Normally I'd suspect some kind of software conflict, but this started virtually straight out of the box. Is there some prefs file or other element that might be corrupting my system? Is there another way to install software other than using Safe Boot mode?