Related to https://idempiere.atlassian.net/browse/IDEMPIERE-1675 i was wondering why there are entries in AD_Preference which had no UUID. Searching for "AD_Preference" brought to light, that there are some places where inserting stuff into ad_preference is done with sql instead of using a model. I think, the AD_Preference_UU column is missing in these sql statements.

The places are, as far as i can tell:
-org.compiere.grid.ed.ValuePreference.insert()
-org.adempiere.webui.ValuePreference.insert()
-org.compiere.model.MSetup.createPreference(String, String, int)