This applies to sites using the Serials Solutions AZ Database import. This import is currently not working due to an issue on the Ex Libris end. The error was introduced over the weekend of 6/18-6/19.
Ex Libris is aware of this problem and working on a fix. We are in close communication with them and will post here with any updates as soon as they make us aware.
Update: 7/14/2022 11:00AM ET - Following an update from ProQuest/Ex Libris, the Serial Solutions A-Z Database Import is now working normally.