in the hidden required field, you have to include the name of item selected in the select options, note: this is not necessarily the name of the select option but the item that is pre-selected to show by default in the web page
ie
select name = menu
preselected item = firstitem <- include required
I found the answer,
in the hidden required field, you have to include the name of item selected in the select options, note: this is not necessarily the name of the select option but the item that is pre-selected to show by default in the web page
ie
select name = menu
preselected item = firstitem <- include required