set nil for optional property issue

[Bobo Shone]

Got an error "Attempt to insert non-property list object null for key" when set nil for optional property.
I want to remove from UserDefaults by setting to nil, but got a <null> new value from KVO. Don't know how to check <null>. thanks

[JD Gadina]

Should now be fixed.
You can use nil to remove a value.