Help needed with wlappc unrecognized in build.xml weblogic 12.2.4 ( java 1.8)

We are upgrading our application from Weblogic 12.1.0 to 12.2.4 and build script failed with following error : Problem: failed to create task or type wlappc

Cause: The name is undefined.

This part works fine in our current environment ( weblogic 12.1.0 – java 1.6 , ANT 7.1 )

Build.xml is same between environments ( by making sure the classpath and other stuff pointed to new weblogic )

Build.xml has simple wlappc command with Basic format :

<wlappc source="${build-deployment}/${Project}-Deployment.jar" verbose="true" >

<classpath>

<pathelement path="${env.CLASSPATH}"/>

<pathelement path="${build-classes}"/>

<pathelement path="${dependency-classpath}"/>

</classpath>

</wlappc>

Error it shows as follows :

Problem: failed to create task or type wlappc Cause: The name is undefined.