Resolution:
Please do the following steps for proper migration:

     a) Take a back up of your project
     b) Open the project in TIBCO Designer and select the adapter configuration.
     c) Select the Configuration tab and click on Change Version button
     d) Select "AE Version 5.X" and save the project
     e) Click on the adapter services and select ‘Schema’ tab. Do a refresh schema
     f) Convert the project to dat file and check whether the dat file is getting generated as expected.