Can't re-import a reviewed Word file with the Retrofit feature in batch tasks

Dear Studio 2015 expert(s):

I tried to update a Studio file with a reviewed Word file using the Retrofit function in batch tasks but the process failed with the following message:

Index must be within the bounds of the List.  Parameter name: index

Does anyone know how to solve the problem?  I tried the Word file with track changes and one with changes accepted and received the same message both times.

Thank you.

Chunyi