I am receiving this notification for a custom field. Please advise how to remove this field from screen.

I do change field config, project and issue type scope to another field from
"Start Date" to "Start date".
Because this field is has to be "required" field, but i want to change that to "non required" field (i can't change the option from required to optional because the other field was associated with another screen in another project).

And field "Start date" appeared

But still, i got this notification
