Course shows error when you try to add to completed course

If you see the following message appear when you try to add a completed course to a students record " missing text" 

This means the code has been expired in the codes table and cannot be used, the save button will never become available. 

You must choose another code that has not been expired in the codes table. 

If the student took this course and needs to be added to the transcript you may choose this code and add the date that reflects when the code was active. For example, the code was active from 01/01/2020 to 01/01/2022 you can add any date between those dates like 01/03/2021