Library Not Registered error in SAP B1 8.8 PL 12

Hello Experts,

Whenever i use following code in SAP B1 8.8 PL 12 i get error as library not registered.

If oMatrix.Columns.Item("V_14").Cells.Item(pVal.Row).Specific.selected.value.Equals("") = False Then

or

oMatrix.Columns.Item("V_14").Cells.Item(pVal.Row).Specific.Value=a

The above code works fine in SAP B1 2007 B

Please suggest which dll file is missing

error comes wherever .Value is written in code

Please Suggest

Quick reply will be very helpful