Build fails with Access Denied error

I tried running VS as administrator but no luck.



1>Build:
1>  Building UnrealHeaderTool...
1>EXEC : error : System.ComponentModel.Win32Exception (0x80004005): Access is denied
1>     at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
1>     at System.Diagnostics.Process.Start(ProcessStartInfo startInfo)
1>     at UnrealBuildTool.ExternalExecution.RunExternalExecutable(String ExePath, String Commandline) in c:\Users\Mark\Documents\GitHub\UnrealEngine\Engine\Source\Programs\UnrealBuildTool\System\ExternalExecution.cs:line 353
1>     at UnrealBuildTool.ExternalExecution.ExecuteHeaderToolIfNecessary(UEBuildTarget Target, List`1 UObjectModules, String ModuleInfoFileName, ECompilationResult& UHTResult) in c:\Users\Mark\Documents\GitHub\UnrealEngine\Engine\Source\Programs\UnrealBuildTool\System\ExternalExecution.cs:line 420
1>     at UnrealBuildTool.UEBuildTarget.Build(List`1 OutputItems) in c:\Users\Mark\Documents\GitHub\UnrealEngine\Engine\Source\Programs\UnrealBuildTool\Configuration\UEBuildTarget.cs:line 1420
1>     at UnrealBuildTool.UnrealBuildTool.RunUBT(String] Arguments) in c:\Users\Mark\Documents\GitHub\UnrealEngine\Engine\Source\Programs\UnrealBuildTool\System\UnrealBuildTool.cs:line 1085
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.MakeFile.Targets(38,5): error MSB3073: The command "..\..\Build\BatchFiles\Build.bat UE4Editor Win64 Development" exited with code -1.


How do I fix this?

I have had same issue after “Clean”. Fixed only by full reinstall.