return patientVisitVar> depends on vIPIndicator is neither defined in the script nor in dependencies??

hi; What does this error mean :

return patientVisitVar> depends on vIPIndicator is neither defined in the script nor in dependencies.
at org.bonitasoft.engine.expression.impl.GroovyScriptExpressionExecutorCacheStrategy.evaluate(GroovyScriptExpressionExecutorCacheStrategy.java:148)
at org.bonitasoft.engine.expression.impl.ExpressionServiceImpl.evaluate(ExpressionServiceImpl.java:89)
at org.bonitasoft.engine.core.expression.control.api.impl.ExpressionResolverServiceImpl.evaluateExpressionWithResolvedDependencies(ExpressionResolverServiceImpl.java:234)
at org.bonitasoft.engine.core.expression.control.api.impl.ExpressionResolverServiceImpl.evaluateExpressionsFlatten(ExpressionResolverServiceImpl.java:127)
at org.bonitasoft.engine.core.expression.control.api.impl.ExpressionResolverServiceImpl.evaluate(ExpressionResolverServiceImpl.java:86)
at org.bonitasoft.engine.core.operation.impl.OperationServiceImpl.evaluateRightOperandExpression(OperationServiceImpl.java:218)
... 24 more
Caused by: groovy.lang.MissingPropertyException: No such property: vIPIndicator for class: com.company.model.PV1$HibernateProxy$1ukH8VKU
Possible solutions: VIPIndicator