3502063 - Cost Centre is required in Alternative Cost Distribution - Employee Central

We are using standard object with custom field for WBS - when we key in WBS only, system prompts that Cost Centre is required.  
Where is the validation coming from and can this be disabled? 

SAP SuccessFactors Employee Central

1. Access the instance
2. Go to the profile of the user
3. Scroll to Alternative Cost Distribution
4. Click in Insert New Record
5. Fill the fields and leave Alternative Cost Center blank
6. Save record
7. System prompts Cost Centre is required

Such an object level customization where making the cost center non mandatory is not possible and there are validations to make sure cost center is filled always

Managing Cost Object Assignment for an Employee | SAP Help Portal

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SAP SuccessFactors Employee Central all versions ; SAP SuccessFactors HCM Suite all versions