RemoveInvalidFieldReferencesFromScreens.groovy

import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.fields.FieldManager
import com.atlassian.jira.issue.fields.screen.FieldScreenManager

def fieldScreenManager = ComponentAccessor.getComponent(FieldScreenManager)
def fieldManager = ComponentAccessor.getComponent(FieldManager)

// change to false to remove invalid fields
def preview = true

fieldScreenManager.fieldScreens.each { screen ->
    screen.tabs.each { tab ->
        tab.fieldScreenLayoutItems.findAll { layoutItem ->
            !fieldManager.getField(layoutItem.fieldId)
        }.each { layoutItem ->
            log.warn("Missing field: $layoutItem.fieldId on screen: '$screen.name', tab: '${tab.name}'")

            if (!preview) {
                tab.removeFieldScreenLayoutItem(layoutItem.position)
            }
        }
    }
}