iTunes won't authorize my computer now with Windows 10

My laptop is authorized for content on my iPhone 6 (Audible, music, etc.). Now that I've updated to Windows OS 10, when I connect my iPhone6, I get message that my computer is not authorized and my purchased content will be removed from my iPhone. When I go to iTunes/Account/Authorize this computer and enter my iTunes log-on info/pw- I get iTunes box/message "We could not complete your ITunes Store request. The requested resource was not found. There was an error in the iTunes Store. Please try again later." Why won't it allow me to re-authorize my computer and why did this happen since I upgraded to Windows 10?