When i try in my dve client it is allowing to craete diff valuation class for same mateial in diff palnt.
When i try the same in DEV client of customer system it is not allowing and giving message as " Check valuation classs and message no is SY002"
How to fix this
You can assign different valuation class to a material in different plant in the Material Master. Provided that the Valuation class has been defines and assigned to the same Account Category Reference in Customizing TCode - OMSK.
Hope it helps.