Thanks for report Wai.
This is not specific to ecomseo and exists also in ecommerce.
It seems to be due to a regression introduced with http://svn.apache.org/viewvc?view=revision&revision=1721092
But when I (only) revert those 2 lines I get this error:
Type check failed for field [createShoppingListRecurrence.startDateTime]; expected type is [Timestamp]; actual type is [java.util.LinkedList]
Could you please continue from this?
Note: also in ecomseo and ecommerce you can't can't edit a shopping list (top "Edit" button). It works at https://localhost:8443/partymgr/control/updateShoppingList. Could you please create another Jira for that?