I convert primavera xer file in to mpx formate using MPXWriter class. File converted successfully into mpx format. But when i will try to import file in primavera p6 software its give error
Import/Export Error: Cannot find a unique value for wbs_short_name in PROJWBS. Last value is 109989 L3 - LIVE X.12.1.109989 - Const.1008
I am getting this above error. attached screen short as per below. please help me for solved this issue.

If you have an XER file you shouldn't convert it to MPX. Either import it as is or, if its version is higher than P6 version, open the XER file in notepad and modify the version.