Resolution:
The format of an MB 3.2 sheet as saved in a repository is different from that of MB 3.1.x.
MB 3.2 runtime can understand a sheet that was saved with MB 3.1.x.  The first time that you load such a sheet in the MB 3.2 GUI, MB will do the appropriate conversions.  When you then save the transform, it is saved in the MB 3.2 format. So this is a one time operation that you need to do for each MB 3.1.x worksheet that you want to "convert" to MB 3.2.

NOTE: MB 3.1.x is NOT forward compatible with MB 3.2 meaning you cannot load a sheet in MB 3.1.x that was saved with MB 3.2.