Unable to build/package a simple Android project (The system file could not be specified)

I’m trying to basically create a “Hello World” style Android application (just the “Blank” project template) as a first step toward creating an Oculus Go application. I’ve followed the Quick Start guides for Android and Oculus Go as best I can, but I’m still unable to build. I’m really new to Android packaging, so there may be something simple going wrong, but I can’t seem to figure out the error messages.

Below is a portion of the output log that seems relevant. If there’s any easier way to display this, let me know! **Asterisks** used to indicate lines that were in red.

UATHelper: Packaging (Android (ETC1)): ====6/25/2018 2:53:39 PM====PREPARING NATIVE CODE=================================================================
UATHelper: Packaging (Android (ETC1)): On build machine.
UATHelper: Packaging (Android (ETC1)): Fixing minSdkVersion; NDK level above 19 requires minSdkVersion of 21 (arch=armv7)
UATHelper: Packaging (Android (ETC1)): Copying permission_library directory to staging before build
UATHelper: Packaging (Android (ETC1)): Directory C:\Program Files\Epic Games\UE_4.19/Engine/Source/ThirdParty/AndroidPermission/permission_library copied to C:\UnrealAndroidProjects\OculusGoTest_04\Intermediate/Android/APK/JavaLibs/permission_library
UATHelper: Packaging (Android (ETC1)): ====6/25/2018 2:53:39 PM====UPDATING BUILD CONFIGURATION FILES====================================================
**UATHelper: Packaging (Android (ETC1)): ERROR: System.ComponentModel.Win32Exception (0x80004005): The system cannot find the file specified**
UATHelper: Packaging (Android (ETC1)):           at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
UATHelper: Packaging (Android (ETC1)):           at UnrealBuildTool.UEDeployAndroid.RunCommandLineProgramWithException(String WorkingDirectory, String Command, String Params, String OverrideDesc, Boolean bUseShellExecute)
UATHelper: Packaging (Android (ETC1)):           at UnrealBuildTool.UEDeployAndroid.UpdateProjectProperties(AndroidToolChain ToolChain, String UE4BuildPath, String ProjectName)
UATHelper: Packaging (Android (ETC1)):           at UnrealBuildTool.UEDeployAndroid.MakeApk(AndroidToolChain ToolChain, String ProjectName, String ProjectDirectory, String OutputPath, String EngineDirectory, Boolean bForDistribution, String CookFlavor, Boolean bMakeSeparateApks, Boolean bIncrementalPackage, Boolean bDisallowPackagingDataInApk, Boolean bDisal
UATHelper: Packaging (Android (ETC1)):           at UnrealBuildTool.UEDeployAndroid.PrepForUATPackageOrDeploy(FileReference ProjectFile, String ProjectName, DirectoryReference ProjectDirectory, String ExecutablePath, String EngineDirectory, Boolean bForDistribution, String CookFlavor, Boolean bIsDataDeploy)
UATHelper: Packaging (Android (ETC1)):           at AndroidPlatform.Package(ProjectParams Params, DeploymentContext SC, Int32 WorkingCL)
UATHelper: Packaging (Android (ETC1)):           at Project.Package(ProjectParams Params, Int32 WorkingCL)
UATHelper: Packaging (Android (ETC1)):           at BuildCookRun.DoBuildCookRun(ProjectParams Params)
UATHelper: Packaging (Android (ETC1)):           at BuildCookRun.ExecuteBuild()
UATHelper: Packaging (Android (ETC1)):           at AutomationTool.BuildCommand.Execute()
UATHelper: Packaging (Android (ETC1)):           at AutomationTool.Automation.Execute(List`1 CommandsToExecute, Dictionary`2 Commands)
UATHelper: Packaging (Android (ETC1)):           at AutomationTool.Automation.Process(String[] Arguments)
UATHelper: Packaging (Android (ETC1)):           at AutomationTool.Program.MainProc(Object Param)
UATHelper: Packaging (Android (ETC1)):           at AutomationTool.InternalUtils.RunSingleInstance(Func`2 Main, Object Param)
UATHelper: Packaging (Android (ETC1)):           at AutomationTool.Program.Main()
UATHelper: Packaging (Android (ETC1)):        (see C:\Users\My UserName\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_4.19\UAT_Log.txt for full exception trace)
UATHelper: Packaging (Android (ETC1)): AutomationTool exiting with ExitCode=1 (Error_Unknown)
**PackagingResults: Error: System.ComponentModel.Win32Exception (0x80004005): The system cannot find the file specified**
UATHelper: Packaging (Android (ETC1)): BUILD FAILED
**PackagingResults: Error: Unknown Error**

I’ve been banging my head against the wall for days. Any help would be greatly appreciated!