Q: cannot access itunes store in china

iTunes 12.3.0.44 - just updated but even before this update this has been happening.

Trying to get to the store times out in iTunes: "an unknown error occured - 0x80090318"

I can get to iTunes.com, I can get to the store on the iPad itself (iPad 2).

Also, the iPad will not complete a sync.  It says "there are items on the iPad not present in iTunes, back them up or lose them?"  I say back them up, it gets about 30% done, then just sits for hours.

I was able to update the iPad to 9.0.1 via wifi.

Help.