Today, SA immigration has sent out a newsletter providing information about their temporary closure of migration program to make mandatory changes in their system to accommodate the changes taking effect in the new financial year 2019 - 2020.
According to the article, the General Skilled Migration (GSM) state nomination 190/489 application system will be closed from 9am on Monday 24 June and will re-open in the first week of July (the date and time will be confirmed at the start of July).
From 9am on 24 June, incomplete applications will be deleted, this includes applications that have been saved but not submitted and applications that have been submitted but are still awaiting payment .
Source: https://www.migration.sa.gov.au/news-events/news-releases/2998