Groovy Script Error concerning INT variable

Summary:

When running a groovy script, we are receiving the following error:

method called by the script failed on line: 165, with error: Viewpoint Master completed with errors.

Log messages :
Starting Groovy script...
Setting Variables...
dataLoadType selected is Nightly
Periods assigned by function [Oct-25]
Beginning processing data...
Running period: Oct-25
running pipeline: 001GL
company: 1, period: Oct-25, jobId: 29303, data load id: 29306, status: 0
running pipeline: 021GL
Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead
null
org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead