I have a few Windows 2012 R2 servers that all of a sudden won't let me remote desktop to them from my Windows 7 SP1 machine. If I put the server name in RDP, it comes back with "authentication error has occurred Code 0x80004005". If I put the ip address in it works.
Before you go saying it's DNS, if I turn off NLA it works with just the server name. My RDP software says it is "NLA supported".