I just tried to pack my project but it being failed while building and here is my log
LogPlayLevel: Running AutomationTool...
LogPlayLevel: Automation.ParseCommandLine: Parsing command line: -ScriptsForProject=F:/BACKUP_DEVELOPMENT_1/Unreal/PENDULUM/PENDULUM.uproject BuildCookRun -project=F:/BACKUP_DEVELOPMENT_1/Unreal/PENDULUM/PENDULUM.uproject -noP4 -clientconfig=Debug -serverconfig=Debug -nocompile -nocompileeditor -installed -ue4exe=UE4Editor-Cmd.exe -utf8output -platform=Win64
-targetplatform=Win64 -build -map=/Game/StarterContent/Maps/5_pendulum -skipcook -CookInEditor -iterativecooking -compressed -iterativedeploy -stage -deploy -cmdline="/Game/StarterContent/Maps/5_pendulum -Messaging" -device=WindowsNoEditor@DEVELOPMENT-1 -addcmdline="-SessionId=8A9CB8AC464D4493AD2ADC8C9CBDD68F -SessionOwner='Gaming i7' -SessionName='Launch O
n Device' " -run
LogPlayLevel: BuildCookRun.SetupParams: Setting up ProjectParams for F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject
LogPlayLevel: Project.Build: ********** BUILD COMMAND STARTED **********
LogPlayLevel: Completed Launch On Stage: Build Task, Time: 1.003486
LogPlayLevel: CommandUtils.Run: Run: C:\UE_4.16\Engine\Binaries\DotNET\UnrealBuildTool.exe PENDULUM Win64 Debug -Project=F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject -NoUBTMakefiles -remoteini="F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM" -noxge -generatemanifest -NoHotReload
LogPlayLevel: CommandUtils.Run: Run: Took 0.9204988s to run UnrealBuildTool.exe, ExitCode=0
LogPlayLevel: CommandUtils.Run: Run: C:\UE_4.16\Engine\Binaries\DotNET\UnrealBuildTool.exe PENDULUM Win64 Debug -Project=F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject -NoUBTMakefiles -remoteini="F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM" -noxge -NoHotReload -ignorejunk
LogPlayLevel: UnrealBuildTool: Performing 2 actions (4 in parallel)
LogPlayLevel: UnrealBuildTool: MyPlayerController1.cpp
LogPlayLevel: UnrealBuildTool: C:\UE_4.16\Engine\Source\Editor/LevelEditor/Public/LevelEditorActions.h(8): fatal error C1083: Cannot open include file: 'UnrealWidget.h': No such file or directory
LogPlayLevel: UnrealBuildTool: ERROR: UBT ERROR: Failed to produce item: F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\Binaries\Win64\PENDULUM-Win64-Debug.exe
LogPlayLevel: UnrealBuildTool: Total build time: 4.12 seconds (Local executor: 0.00 seconds)
LogPlayLevel: CommandUtils.Run: Run: Took 4.2815691s to run UnrealBuildTool.exe, ExitCode=5
LogPlayLevel: Program.Main: ERROR: AutomationTool terminated with exception: AutomationTool.CommandUtils+CommandFailedException: Command failed (Result:5): C:\UE_4.16\Engine\Binaries\DotNET\UnrealBuildTool.exe PENDULUM Win64 Debug -Project=F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM\PENDULUM.uproject -No
UBTMakefiles -remoteini="F:\BACKUP_DEVELOPMENT_1\Unreal\PENDULUM" -noxge -NoHotReload -ignorejunk. See logfile for details: 'UnrealBuildTool-2017.10.26-18.00.59.txt'
LogPlayLevel: at AutomationTool.CommandUtils.RunAndLog(String App, String CommandLine, String Logfile, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary`2 EnvVars, SpewFilterCallbackType SpewFilterCallback)
LogPlayLevel: at AutomationTool.CommandUtils.RunAndLog(CommandEnvironment Env, String App, String CommandLine, String LogName, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary`2 EnvVars, SpewFilterCallbackType SpewFilterCallback)
LogPlayLevel: at AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, String CommandLine, String LogName, Dictionary`2 EnvVars)
LogPlayLevel: at AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, FileReference Project, String Target, String Platform, String Config, String AdditionalArgs, String LogName, Dictionary`2 EnvVars)
LogPlayLevel: at 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, Dictionary`2 EnvVars)
LogPlayLevel: at AutomationTool.UE4Build.Build(BuildAgenda Agenda, Nullable`1 InDeleteBuildProducts, Boolean InUpdateVersionFiles, Boolean InForceNoXGE, Boolean InUseParallelExecutor, Boolean InForceNonUnity, Boolean InForceUnity, Boolean InShowProgress, Dictionary`2 PlatformEnvVars, Nullable`1 InChangelistNumberOverride, Dictionary`2 InTargetToManifest)
LogPlayLevel: at Project.Build(BuildCommand Command, ProjectParams Params, Int32 WorkingCL, ProjectBuildTargets TargetMask)
LogPlayLevel: at BuildCookRun.DoBuildCookRun(ProjectParams Params)
LogPlayLevel: at BuildCookRun.ExecuteBuild()
LogPlayLevel: at AutomationTool.BuildCommand.Execute()
LogPlayLevel: at AutomationTool.Automation.Execute(List`1 CommandsToExecute, CaselessDictionary`1 Commands)
LogPlayLevel: at AutomationTool.Automation.Process(String[] Arguments)
LogPlayLevel: at AutomationTool.Program.MainProc(Object Param)
LogPlayLevel: at AutomationTool.InternalUtils.RunSingleInstance(Func`2 Main, Object Param)
LogPlayLevel: at AutomationTool.Program.Main()
LogPlayLevel: Program.Main: AutomationTool exiting with ExitCode=5 (5)
LogPlayLevel: Completed Launch On Stage: Build Task, Time: 4.760066
LogPlayLevel: BUILD FAILED
PackagingResults:Error: Error Launch failed! Unknown Error