Wow!! I just purchase4d this 6515 unit last week, finally put it inservive yesterday.... Seeing this problem being posted and ignorred by xerox "support" alot... Yes, have the same problem as many other posting users are having along with a few other network communications problems. In short this unit is the biggest unable to deliver on promised services and functions unit I have ever owned and the complete lack of help from xerox makes it a really bad purchase. I'm not going to screw with days and days of nonfunctionality and poor customer support. I am going to return the unit under the retailer's 30 day satisfaction policy and buy another Hewlette Packard unit who's units have always set up, performed easily and worked as advertised out of the box. This was a replacement for a 9 year old HP CMF1312 NPI, and abosulutely no match for it! I made the decision to purchase the xerox 6515 thinking it was a business class machine, backed by a reputable business class company.... the total lack of any interest in providing support or a solution to this and other problems tells me I was wrong.
Oh and for other posters seeking some solutions to problems encountered with driver issues... I used the Windows Device Services to add the unit to all of my machines here after completely removing all of the problematic xerox drivers and files from my machines. This was the best solution to most of the buggy driver issues I experienced on the first attempts to install and get the Xerox 6515 unit up and running acceptably on all of my equipment. Believe it or not the Windows native drivers work better than the vendor drivers in the case of the Xerox 6515, everthing communicates as it should except the scanner/fax. This as the OP noted can be solved using the older out dated WIA drives uinstead of the more perferred TWAIN which means having to use the Xerox supplied driver application which does work (fails to communicate)! Yea...for real, the Windows drivers were better this time!! I have both Windows 10 pro and yet one Windows 7 pro machines all working in harmony on my little local work place network with the exception of this new Xerox 6515. My advise on this unit is to avoid it unless you have a good $100,000.00 annual salary IT pro employed in your small business who can spend his days screwing with your Xerox machines to make sure they play nice. Me, nope... small self managed situation in which I cannot spend the majority of my time baby sitting and pampering a multifunction printer unit to get it to work as it should out of the box!
I misplaced my confidence in Xerox's **bleep** & hype... don't make the same mistake folks. As I have witnessed on multiple posts from different people on Xerox's "support forum" alone support for this and other issues is not very forthcoming.
Good Luck All!