Reproduction steps:
1. Open any project
2. Try to build to a shared folder on a remote machine
3. Fails with following output:

DirectoryNotFoundException: Directory '\SURFACEPRO2_02\New Unity Project' not found.
System.IO.Directory.GetFileSystemEntries (System.String path, System.String searchPattern, FileAttributes mask, FileAttributes attrs) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.IO/Directory.cs:514)
System.IO.Directory.GetFiles (System.String path, System.String searchPattern) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.IO/Directory.cs:308)
UnityEditor.WindowsStandalone.WindowsDesktopStandalonePostProcessor.DeleteDestination () (at C:/buildslave/unity/build/PlatformDependent/WinPlayer/Extensions/Managed/WindowsDesktopStandalonePostProcessor.cs:67)
DesktopStandalonePostProcessor.CopyStagingAreaIntoDestination () (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/DesktopStandalonePostProcessor.cs:224)
DesktopStandalonePostProcessor.PostProcess () (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/DesktopStandalonePostProcessor.cs:25)
UnityEditor.WindowsStandalone.WindowsDesktopStandalonePostProcessor.PostProcess (BuildPostProcessArgs args) (at C:/buildslave/unity/build/PlatformDependent/WinPlayer/Extensions/Managed/WindowsDesktopStandalonePostProcessor.cs:151)
UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, System.String downloadWebplayerUrl, System.String manualDownloadWebplayerUrl, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.BuildReporting.BuildReport report) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:186)
UnityEditor.HostView:OnGUI()

Introduced in 5.5.0b4