If you get the following error message.

"Option Tab Fields and/or Configurable Fields are NOT COMPLETED. Click on the Tabs and complete the fields."

When using the product availability page or when trying to add a new order, it means you have not completed all required fields.

In the section window click on the tab Options


and check that all required fields are completed.

Then if there is a Configurable Fields tab as well click on this tab


and check that all required fields in this tab have been correctly answered as well.