In FIX Module 7.2, field names and the field structure have changed in the ApplicationMessage part of some version 4.4 FIX message IS document types. When you install FIX Module 7.2, the current versions of the IS document types are also installed. However, if you have modified any of the affected IS document types in FIX Module 6.5 and want to keep your custom fields, you must manually update the corresponding IS document types installed with FIX Module 7.2.