Returned Form Response File "Has Different Fields" - Does not match with the other returned forms

I am collecting data from a form I created and sent out to several recipients.  I have created the response file and have correctly added Returned Forms.  My issue is that for two response forms, it appears that the participant somehow changed the field names, and for these two sets of data, they "have different fields."  I need the data from all data sets to align properly, otherwise I cannot do the appropriate analysis of the information.  Is there a way to fix this?  Is there a way to fix the field names on the returned form so that it matches with the rest of the other returned forms' field names?