Have you found the cause of the problem ? It happened to me too… when packaging from the project launcher
here is the Log :
BUILD FAILED
E:\NVIDIA\android-sdk-windows ools\ant\build.xml:871: Can’t read [E:\NVIDIA\android-sdk-windows\platforms\android-28\android.jar] (Can’t process class [android/Manifest.class] (Unsupported class version number [52.0] (maximum 51.0, Java 1.7)))
Total time: 48 seconds
ERROR: C:\WINDOWS\system32\cmd.exe failed with args /c “E:/NVIDIA/apache-ant-1.8.2/bin/ant.bat” release -Djava.source=1.7 -Djava.target=1.7
(see C:\Users\Daniel Christian\AppData\Roaming\Unreal Engine\AutomationTool\Logs\E+Program+Files+UE_4.22\Log.txt for full exception trace)
AutomationTool exiting with ExitCode=1 (Error_Unknown)
BUILD FAILED
Can you solved it? or is there anybody can solved it?