I'm deploying an Apex Class from a Dev sandbox to a Full and getting a compile error that I did not get in the Dev sandbox.  The error is Compile Error: Invalid type: SRMapping__c.   Any ideas?

Here's the first part of the code:

public with sharing class oppProductFieldSelExtension {
   //List that holds all Selection Items
    public List<ExtendedProduct> selection {get;set;}
        public List<ProdOppLineWrapper> oppSelections{get; set;}
        public List<OpportunityLineItem> existingItems {get; set;}
        public String oppID {get; set;}
        public Opportunity oppRec {get; set;}
        public ProductsIDTracker__c prodTracker {get; set;}
        public List<PriceBookEntry> prodPriceBkList {get; set;}
        public List<String> productIDs{get; set;}
        public List<String> prodPriceBkIDs{get; set;}
        //public list<selectOption> sensor_Resolution {get;set;}      
    //soql string without the order and limit      
    private String soql {get;set;}
    //the collection of products to display
    public List<ExtendedProduct> products {get;set;}
    //Product Family list
    private List<String> productFamilies;
    //String to hold selected Family
    private String selectedFamily;
    //Pricebook to look at
    private list<Pricebook2> pricebook;
    //Map of Field Names and Description of that field
    Map<String,Schema.SObjectField> fields;
    private String selectedField;
    private String selectedOperator;
    private String fieldSearch;
    private String quickSearch;   
    public List<selectOption> resolutionList {get;set;}
    //public String sensorKeys {get; set;}
   
    //public String sensor {get;set;}
   
    public map<String, SRMapping__c> mapResolution1 {get;set;}   
   
         public String getselectedOperator()
        {
                return this.selectedOperator;
        }
        public void setselectedOperator(String s)
        {
                this.selectedOperator = s;
        }