Hello!
I just updated my Project from 4.19 to 4.20 and now, when I try to launch the game on an android device I get the following error:
====21.07.2018 00:06:05====PERFORMING FINAL APK PACKAGE OPERATION================================================
LogPlayLevel: Creating rungradle.bat to work around commandline length limit (using unused drive letter Z:)
LogPlayLevel: Making .apk with Gradle...
LogPlayLevel: To honour the JVM settings for this build a new JVM will be forked. Please consider using the daemon: https://docs.gradle.org/4.1/userguide/gradle_daemon.html.
LogPlayLevel: FAILURE: Build failed with an exception.
LogPlayLevel: * What went wrong:
LogPlayLevel: java.io.IOException: Unable to establish loopback connection
LogPlayLevel: * Try:
LogPlayLevel: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
LogPlayLevel: * Get more help at https://help.gradle.org
LogPlayLevel: ERROR: cmd.exe failed with args /c "A:\Unreal Engine\EndlessFly4.18\Intermediate/Android/APK\gradle\rungradle.bat" :app:assembleDebug
LogPlayLevel: (see C:\Users\mbcub\AppData\Roaming\Unreal Engine\AutomationTool\Logs\A+Programme+EpicGames+Epic+Games+UE_4.20\Log.txt for full exception trace)
LogPlayLevel: AutomationTool exiting with ExitCode=1 (Error_Unknown)
LogPlayLevel: Completed Launch On Stage: Deploy Task, Time: 4.013902
LogPlayLevel: BUILD FAILED
PackagingResults: Error: Launch failed! Unknown Error
Log.txt:
UEDeployAndroid.RunCommandLineProgramWithException: Making .apk with Gradle...
<>c.<PrintExceptionInfo>b__4_1: ==============================================================================
<>c.<PrintExceptionInfo>b__4_0: ERROR: cmd.exe failed with args /c "A:\Unreal Engine\EndlessFly4.18\Intermediate/Android/APK\gradle\rungradle.bat" :app:assembleDebug
<>c.<PrintExceptionInfo>b__4_0: (see C:\Users\mbcub\AppData\Roaming\Unreal Engine\AutomationTool\Logs\A+Programme+EpicGames+Epic+Games+UE_4.20\Log.txt for full exception trace)
<>c.<PrintExceptionInfo>b__4_1:
<>c.<PrintExceptionInfo>b__4_1: BuildException: cmd.exe failed with args /c "A:\Unreal Engine\EndlessFly4.18\Intermediate/Android/APK\gradle\rungradle.bat" :app:assembleDebug
<>c.<PrintExceptionInfo>b__4_1: bei UnrealBuildTool.UEDeployAndroid.RunCommandLineProgramWithException(String WorkingDirectory, String Command, String Params, String OverrideDesc, Boolean bUseShellExecute) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Platform\Android\UEDeployAndroid.cs:Zeile 1406.
<>c.<PrintExceptionInfo>b__4_1: bei UnrealBuildTool.UEDeployAndroid.MakeApk(AndroidToolChain ToolChain, String ProjectName, TargetType InTargetType, String ProjectDirectory, String OutputPath, String EngineDirectory, Boolean bForDistribution, String CookFlavor, Boolean bMakeSeparateApks, Boolean bIncrementalPackage, Boolean bDisallowPackagingDataInApk, Boolean bDisallowExternalFilesDir) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Platform\Android\UEDeployAndroid.cs:Zeile 3838.
<>c.<PrintExceptionInfo>b__4_1: bei UnrealBuildTool.UEDeployAndroid.PrepForUATPackageOrDeploy(FileReference ProjectFile, String ProjectName, DirectoryReference ProjectDirectory, String ExecutablePath, String EngineDirectory, Boolean bForDistribution, String CookFlavor, Boolean bIsDataDeploy) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Platform\Android\UEDeployAndroid.cs:Zeile 3990.
<>c.<PrintExceptionInfo>b__4_1: bei AndroidPlatform.Deploy(ProjectParams Params, DeploymentContext SC) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Android\AndroidPlatform.Automation.cs:Zeile 1012.
<>c.<PrintExceptionInfo>b__4_1: bei Project.Deploy(ProjectParams Params) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\DeployCommand.Automation.cs:Zeile 56.
<>c.<PrintExceptionInfo>b__4_1: bei BuildCookRun.DoBuildCookRun(ProjectParams Params) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\BuildCookRun.Automation.cs:Zeile 222.
<>c.<PrintExceptionInfo>b__4_1: bei BuildCookRun.ExecuteBuild() in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\BuildCookRun.Automation.cs:Zeile 41.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.BuildCommand.Execute() in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\BuildCommand.cs:Zeile 112.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.Automation.Execute(List`1 CommandsToExecute, Dictionary`2 Commands) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\Automation.cs:Zeile 562.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.Automation.Process(String[] Arguments, StartupTraceListener StartupListener) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\Automation.cs:Zeile 532.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.Program.MainProc(String[] Arguments, StartupTraceListener StartupListener) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Program.cs:Zeile 174.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.Program.<>c__DisplayClass1_0.<Main>b__0() in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Program.cs:Zeile 100.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.InternalUtils.RunSingleInstance(Func`1 Main) in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\Utils.cs:Zeile 725.
<>c.<PrintExceptionInfo>b__4_1: bei AutomationTool.Program.Main() in D:\Build\++UE4\Sync\Saved\CsTools\Engine\Source\Programs\AutomationTool\Program.cs:Zeile 100.
<>c.<PrintExceptionInfo>b__4_1: ==============================================================================
Program.Main: AutomationTool exiting with ExitCode=1 (Error_Unknown)
Hope you can help me!
And best wishes from Germany! 