URL hacking throwing an error

Question

I have created a URL hacking to populate contract agreement name and account name(through contract agreement) on contract product. For some reasons account name field is showing an error 'Error: Multiple items found. Select from drop-down or click icon to refine search' and is also pulling wrong account name.

Relationship Account is parent to Contract Agreement(Lookup relationship) and contract agreement is parent to contract product(Lookup relationship)

URL hack formula

/a3L/e?CF00N4O000006wG7O={!Contract_Agreement__c.Name}
&CF00N4O000006wG7O_lkid={!Contract_Agreement__c.Id}
&CF00N4O000006wG7N={!Contract_Agreement__c.Account__c}
&00N4O000006wG7N_lkid={!Contract_Agreement__c.AccountId__c}
&retURL=%2F{!Contract_Agreement__c.Id}

Answer 1

If you look at line 4 of your URL

&00N4O000006wG7N_lkid={!Contract_Agreement__c.AccountId__c}

you'll see that the ID is not correct as the custom object Contract_Agreement__c appears (based on your other lines) to use a keyprefix of CF0.

A URL hack that references input fields on the page with invalid Ids simply ignores the URL parameter.

Remember that if you are developing in a sandbox and the fields being referenced in the URL Hack do not yet exist in PROD, the URL will need to be manually edited after deployment as the sandbox field Ids won;t match the PROD field Ids.