I am working on a simple C# WS client using REST protocol.
I successfully added an user with the optional user's preference (using core_user_create_users). When I look into the database, I can see that the preference was inserted into the user_preferences table, but when I retrieve the very same user's data via core_user_get_users function, the response does not contain the preference (neither in JSON nor XML format). All other data seem correct. There is only an empty node in the XML response:
(...) <KEY name="preferences"><MULTIPLE>
It happened with 2.9.2 and the recent 3.0 version, I haven't tried any other versions.
Is this a bug or am I missing something (e.g. should I somehow 'register' the preference via admin's panel?).