Error code 11571

Every time I restart my computer or open iTunes, I get the following message:

"There was a temporary problem completing your request. An unknown error has occurred. (11571)"

I have checked my computer and the software is up-to-date. When I just now plugged my iPhone 6 in to the computer and tried to click on the phone icon to make sure that my software is current, I got this message:

"iTunes cannot read contents of the iPhone. Go to Summary tab in iPhone preferences and click restore to restore this iPhone to its factory settings."

I am not sure if this could be a related problem or not (so far it hasn't been an issue until today): my iTunes account is registered in the US, my iPhone SIM card/telephone number is from the UK, and I am currently living in Sweden.

If I back my phone up to the cloud and then restore the factory settings, will I lose everything or will it all be retrieved off the cloud. Any time I have had to do a factory reset, I was in the US and my phone was backed up to the cloud as well as my computer.

Please advise!

Thanks

Murray