Okay I did this:
cd /var/discourse
./launcher enter app
rails c
Then
UserOption.where.not(dark_scheme_id: nil).find_each do |uo|
uo.update(dark_scheme_id: nil)
end
It worked!
Now when I run the script of data explorer there are no results I also confirmed by opening one user preferences > interface to see if it is checked and yes it is now checked.
Thank you for your help 