This is the reason why the game must do the conversion. And GoMule has never had code to convert Characters / Items from version to another.I can think of a few reasons for the incompatibility between GoMule stashes. For example, GoMule might cut parts of D2R charcter files and shared stashes and copy them into GoMule stashes without knowing all details about the item recordsets. The problem then is that these unknown details have changed which would make a conversion of GoMule stashes impossible. Only Blizzard might know them, so the conversion is to be left to them.
When D2R was launched there were online stash converters Legacy -> D2R (non FAM way).
m4ke