The command that fixed my Apple Store error "can't load data from the apple software update server"

I've been struggling with this for a few days, there is one update at Apple Store, but when I click update, it will give the error message. I tried to remove temp files of Apple Store, repair disk, etc, still the same thing. Today I came cross someone's post, and it worked:

sudo chown -R _softwareupdate:_softwareupdate /var/folders/zz/zyxvpxvq6csfxvn_n00000s0000068