Q:

Error Domain=SKErrorDomain Code=2 "can not connect to iTunes Store" in Production (Subscription)?

I have a user who is getting this error when they try to start a subscription (auto-renewing with free trial for one week) of my app.  I have existing subscribers and this is the first I've heard of it so I don't (think) that it's widespread, but would possibly could be causing it on this users end?  They tried to make the purchase several times in different WIFI/Cellular environments?  There are older posts on this issue but they are primarily when testing IAPs in the sandbox (as opposed to production) and have no clear answer or cause. 

A:

That is the error code for payment cancelled, but I've also seen it occur for users when trying to buy a subscription that they already have access to. 

Have the user check if they are already subscribed (here's the manage subscription url)
See if they are able to restore purchases within your app to get access to subscription

