Having a similar issue myself:
Microsoft SQL Server reported SQL message 229, severity 14: [42000][229][Microsoft]
[sql Server]The EXECUTE permission was denied on the object 'fnGetRelatedContentID', database 'CM_XYZ', schema 'dbo'. Microsoft SQL Server reported SQL message 229, severity 14: [42000][229][Microsoft][sql Server Native Client 11.0][sql Server]The SELECT permission was denied on the object 'SC_SiteDefinition', database 'CM_XYZ', schema 'dbo'.