I've been having the same problem on my iPhone and iPad today. I moved from the US to th UK two years ago but I don't know if that has anything to do with it.
sky is falling..... run
Got the same message on my iPad.
I have changed country in the last year, August last, and I have had nothing but problems with the Apple System since buying an iPad Air about a month ago.
It took me about 2 weeks to get my apps transferred across.
I still cannot get Books, Videos or Films transferred. There are about 18 of those in all - I was fortunate that I choose to use Amazon/Kindle for my book purchases; from them I just accessed Amazon, inserted my password and all the books were on my iPad in next to no time.
I am now starting on transferring my music. The earliest purchase is 2004 so you can imagine how much I have accumulated over 10 years.
Apple are not particularly helpful over this, generally just quoting from the rule book and the manual. To date I far from impressed with their service and competence.
And they want the Apple Reference for each purchase made. I have 35 bundles of receipts on their system (yes, I can access the receipts), with each bundle containing a dozen or so receipts, and there can be between 1 and twenty purchases on each receipt!
I am now going things about it long hand, namely cataloguing everything, finding old backups and such like. However, unlike one or two people on this blog I am not particularly sanguine about Apple "sorting it". I suspect that their system is now starting to show its age, and reflect some of the paranoia implicit in many aspects of Apple design. They are starting to remind me of Microsoft at their zenith.