
Problem:
1. (Contact.Twitter_User_Id__c) External ID and Unique field limit exceeded
The maximum number of external id and unique field for this object has been reached. Please remove the external id or unique field on one of the fields before attempting to add a new one.
Validation Errors While Saving Record(s)
There were custom validation error(s) encountered while saving the affected record(s). The first validation error encountered was "00Di0000000jecJ: VALIDATION_FAILED [Contact.Twitter_User_Id__c: External ID and Unique field limit exceeded: The maximum number of external id and unique field for this object has been reached. Please remove the external id or unique field on one of the fields before attempting to add a new one.]".