SSRS Convert text to Date

 =Format(CDATE(First(Fields!DueDate_SalesInvcHeader.Value, "DataSet_Result")),"dd-MMM-yyyy")

Format of the initialization string does not conform to the OLE DB specification

Use  OLE DB Provider for SQL Server

How to access data form Pervasive SQL in SQL Management Studio

Create Linked Server PERVASIVE using OLEDB Provider for ODBC 

 SELECT * FROM OPENQUERY(PERVASIVE,'SELECT * FROM mytable')