Originally Posted by howetechnical
Try installing the Java SDK (google it) if you don't have it already, that may help. Also, make sure you have only one apk file in the same directory as the sign.bat file, and ensure it's not a zip file but rather an apk.
It was already installed. I just decided to reinstall it again, still same thing. And yeah there is only one apk file in the same directory.
This is so weird