I recently upgraded my daughters 2010 MacBook Air from Yosemite to El Capitan. The upgrade went OK, but since then I have had problems with a few things. It starts up and works fine, including Internet browsing and Time Capsule, until I try and access my NAS or send a print to my network printer. Then it completely locks up and ends up rebooting... Logging into Safe Mode all is fine. So I reinstalled El Capitan on top of the installation, but alas... Then I wiped the SSD and installed El Capitan and all was well, until I imported apps, settings, and profiles from Time Capsule... What's going on?