Existing code for AccountContactRelations, now has errors [duplicate]

Question

I have an existing piece of code that looks for geolocation for existing leads.

 for (Lead l : leads) {
    System.debug(l.Id);
    // Check if Lead was created or Updated for IC_Campaign_Eligible__c in last 24 Hours
    List<LeadHistory> leadHistoryValues = IDtolhist.get(l.id);

    if (!leadHistoryValues.isEmpty()) {
        Double latitude = l.Latitude;
        Double longitude = l.Longitude;
        l.Status = 'ICReady';
        if(l.MG__c == NULL || l.MG__c == ''){
            List<Account> accounts = new List<Account>(
                [SELECT Id, Name, DISTANCE(ShippingAddress, GEOLOCATION(:latitude, :longitude), 'mi' ) Dist,
                    (SELECT ContactId, Contact.Name, Contact.PCP_Counter__c, 
                            Contact.Gender__c 
                      FROM AccountContactRelations 
                      WHERE Contact.Include_in_IC_Campaign__c = TRUE 
                      ORDER BY Contact.PCP_Counter__c ASC NULLS FIRST)
                    FROM Account 
                    WHERE ShippingLatitude != null
                    ORDER BY DISTANCE(ShippingAddress, GEOLOCATION(:latitude, :longitude ),'mi')]);

This was written by someone else and yes - does contain a loop in a loop but...

We are getting an issue with the AccountContactRelation object reference.

This is the error:

Contact.PCP_Counter__c, Contact.Gender__c FROM AccountContactRelations WHERE Contact.Include_in_IC_Campaign__c ^ ERROR at Row:2:Column:145 Didn't understand relationship 'AccountContactRelations' in FROM part of query call. If you are attempting to use a custom relationship, be sure to append the '__r' after the custom relationship name. Please reference your WSDL or the describe call for the appropriate names.

This doesn't make sense. The Object is a standard object; I'm not adding __r in this case. Embedded soql queries work so --- but not in this case...

Can anyone give me a hint as to what may be wrong?

Edit: This is not a duplicate of the other post: This class has been working in production for over a year. It's a scheduled batch class and I was turning on the schedule in full sandbox to test a change in another class but the schedule wouldn't take because of issues in this class (which has not been modified since API V41)

Answer 1

If you are veryfying this in the new sandbox, then make sure that Allow users to relate a contact to multiple accounts setting is enabled in new sandbox i.e. to use AccountContactRelation, you will have to enable this feature.

You can find this from Setup --> Account Settings --> Account Settings