Windows server 2012 R2 Essentials
Windows 7 Workstations
Folder Redirection turned on
Offline files turned off
Basically, every 6 files or so, Office will fail to save a file and say it cannot find the network location of the redirected Documents or Desktop folder. However, it does save a file, only it is blank. Usually, you can then save over that blank file with no additional error. The only recent change is their database program was updated.