Unknown Error

UATHelper: Packaging (Windows (64-bit)): Running AutomationTool…
UATHelper: Packaging (Windows (64-bit)): Automation.ParseCommandLine: Parsing command line: -ScriptsForProject=D:/Farmboyz/FarmBois/Project/FarmBois/FarmBois.uproject BuildCookRun -nocompile -nocompileeditor -installed -nop4 -project=D:/Farmboyz/FarmBois/Project/FarmBois/FarmBois.uproject -cook -stage -archive -archivedirectory=D:/ReleasePreAlpha0.1 -package
-clientconfig=Development -ue4exe=UE4Editor-Cmd.exe -clean -compressed -pak -prereqs -nodebuginfo -targetplatform=Win64 -build -CrashReporter -utf8output
UATHelper: Packaging (Windows (64-bit)): Automation.Process: Setting up command environment.
UATHelper: Packaging (Windows (64-bit)): BuildCookRun.SetupParams: Setting up ProjectParams for D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject
UATHelper: Packaging (Windows (64-bit)): Project.Build: ********** BUILD COMMAND STARTED **********
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files (x86)\Epic Games\4.14\Engine\Binaries\DotNET\UnrealBuildTool.exe FarmBois Win64 Development -Project=D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject -clean D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject -remoteini=“D:\Farmboyz\FarmBois\Project\FarmBois” -nobuil
duht -NoHotReload
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 1,1939898s to run UnrealBuildTool.exe, ExitCode=0
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files (x86)\Epic Games\4.14\Engine\Binaries\DotNET\UnrealBuildTool.exe FarmBois Win64 Development -Project=D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject -remoteini=“D:\Farmboyz\FarmBois\Project\FarmBois” -noxge -gener
atemanifest -NoHotReload -ignorejunk
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 0,8600732s to run UnrealBuildTool.exe, ExitCode=0
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files (x86)\Epic Games\4.14\Engine\Binaries\DotNET\UnrealBuildTool.exe FarmBois Win64 Development -Project=D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject -remoteini=“D:\Farmboyz\FarmBois\Project\FarmBois” -noxge -NoHot
Reload -ignorejunk
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: Creating makefile for FarmBois (no existing makefile)
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: Performing full C++ include scan (no include cache file)
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: ERROR: Windows SDK v8.1 must be installed in order to build this target.
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 2,790486s to run UnrealBuildTool.exe, ExitCode=5
UATHelper: Packaging (Windows (64-bit)): Program.Main: ERROR: AutomationTool terminated with exception: AutomationTool.CommandUtils+CommandFailedException: Command failed (Result:5): C:\Program Files (x86)\Epic Games\4.14\Engine\Binaries\DotNET\UnrealBuildTool.exe FarmBois Win64 Development -Project=D:\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject D:
\Farmboyz\FarmBois\Project\FarmBois\FarmBois.uproject -remoteini=“D:\Farmboyz\FarmBois\Project\FarmBois” -noxge -NoHotReload -ignorejunk. See logfile for details: ‘UnrealBuildTool-2017.01.15-15.11.51.txt’
UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.CommandUtils.RunAndLog(String App, String CommandLine, String Logfile, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary2 EnvVars, SpewFilterCallbackType SpewFilterCallback) UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.CommandUtils.RunAndLog(CommandEnvironment Env, String App, String CommandLine, String LogName, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary2 EnvVars, SpewFilterCallbackType SpewFilterCallback)
UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, String CommandLine, String LogName, Dictionary2 EnvVars) UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, FileReference Project, String Target, String Platform, String Config, String AdditionalArgs, String LogName, Dictionary2 EnvVars)
UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.UE4Build.BuildWithUBT(String TargetName, UnrealTargetPlatform TargetPlatform, String Config, FileReference UprojectPath, Boolean ForceMonolithic, Boolean ForceNonUnity, Boolean ForceDebugInfo, Boolean ForceFlushMac, Boolean DisableXGE, String InAddArgs, Boolean ForceUnity, Dictionary2 EnvVars) UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.UE4Build.Build(BuildAgenda Agenda, Nullable1 InDeleteBuildProducts, Boolean InUpdateVersionFiles, Boolean InForceNoXGE, Boolean InUseParallelExecutor, Boolean InForceNonUnity, Boolean InForceUnity, Boolean InShowProgress, Dictionary2 PlatformEnvVars, Nullable1 InChangelistNumberOverride, Dicti
onary2 InTargetToManifest) UATHelper: Packaging (Windows (64-bit)): bei Project.Build(BuildCommand Command, ProjectParams Params, Int32 WorkingCL, ProjectBuildTargets TargetMask) UATHelper: Packaging (Windows (64-bit)): bei BuildCookRun.DoBuildCookRun(ProjectParams Params) UATHelper: Packaging (Windows (64-bit)): bei BuildCookRun.ExecuteBuild() UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.BuildCommand.Execute() UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.Automation.Execute(List1 CommandsToExecute, CaselessDictionary1 Commands) UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.Automation.Process(String[] Arguments) UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.Program.MainProc(Object Param) UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.InternalUtils.RunSingleInstance(Func2 Main, Object Param)
UATHelper: Packaging (Windows (64-bit)): bei AutomationTool.Program.Main()
UATHelper: Packaging (Windows (64-bit)): Program.Main: AutomationTool exiting with ExitCode=5 (5)
UATHelper: Packaging (Windows (64-bit)): BUILD FAILED
PackagingResults:Error: Error Unknown Error

ERROR: Windows SDK v8.1 must be installed in order to build this target.

Windows SDK appears to be missing.
Hope that helps. Cheers,