Issue 1 : User is unable to delete a list.
Cause: Lists associated with email campaigns cannot be deleted.
Work around: The lists can be hidden using hide option
Issue 2 : in general while trying to hide a list a dialog appears asking” are you sure you want to hide the list?” In case, if you don’t see any message or notice empty dialog box, for reference PFB screenshot then the possibility of this issue could be because of list name having special characters ( like apostrophe).
Solution: Edit and rename the list name such that list name don’t have special characters. Having done that one should be able to hide the list.
