adcfgclone.pl fails in FE node

perl adcfgclone.pl appsTier fails in the front end node with the error message as follows:


Cannot proceed with ApplyApplTop - the paths/ports in the context file are not valid.
RC-20403: The following port numbers are busy - please make sure the ports are available and try again.
Raised by oracle.apps.ad.clone.ApplyAppsTechStack
        s_fnd_cache_port_range :
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Surprisingly, there is no value assigned for this particular variable s_fnd_cache_port_range in the xml file

Solution:
A simple solution is to delete the particular line of s_fnd_cache_port_range and the autoconfig will choose a port value by itself

References:
Oracle Article Ids: 390901.1 & 365871.1
External url: http://blogs.oracle.com/stevenChan/2007/09/java_caching_for_oracle_applic.html