SQL error description: [Microsoft][SQL Server Native Client 11.0][SQL Server]Error: The new name ” is already in use as a COLUMN name and would cause a duplicate that is not permitted.
Solution: I am not very much sure it is the right way or not, but by doing this this error will remove.
Export this table and delete from your customized layer. Now Synch this table and restore.
Now import you code again, this error must remove.