If it is a 2012 R2, ensure the 2012 R2 Server has the update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 that is dated November 2013.
KB2887595
Which includes a fix for KB2896636: You cannot use certain third-party devices to send a document to a shared folder in Windows RT 8.1, Windows 8.1, or Windows Server 2012 R2