Android build failed

ATHelper: Packaging (Android (ETC2)): ERROR: cmd.exe failed with args /c “C:/apache-ant-1.9.4/bin/ant.bat” debug -Djava.source=1.7 -Djava.target=1.7
UATHelper: Packaging (Android (ETC2)): (see C:\Users\username\AppData\Roaming\Unreal Engine\AutomationTool\Logs\F+UE_4.18\UAT_Log.txt for full exception trace)
UATHelper: Packaging (Android (ETC2)): AutomationTool exiting with ExitCode=1 (Error_Unknown)
UATHelper: Packaging (Android (ETC2)): BUILD FAILED
PackagingResults: Error: Unknown Error

Any1 knows problem