Can't Open BTAHL7 Schemas inside WCF workflow service application [BizTalk Mapper]

Hi,

I have created three different BTAHL7 solutions individually for common schemas, acknowledgement & header , HL schema for ADT 28.  

Then created a WCF wokflow service application by adding the above projects as reference to access the above said BTAHL7 schemas inside Biztalk mapper. when I tried to open these schema inside  BizTalk mapper tool (WCF wokflow service application), I got the exception "Schema Collection Exception","Factory Type" as shown in below figure.

Kindly direct me, where am wrong? do i missed to include any configuration?

Please comment.

Thanks,

Dani