Packaging my game for Android 4.20 nvpack

So when I try to package the game for windows it’s fine but when I try to package it for the android it gives me this error:

ERROR: cmd.exe failed with args /c “C:/NVPACK/apache-ant-1.8.2/bin/ant.bat” release -Djava.source=1.7 -Djava.target=1.7

Can somebody help me?