Restarting the Attache Services on the Attache server often resolves this issue. See: Restart or check the Attaché services are running.
If the error comes back, please remove the Attache AppData folder by following the steps below:
Close Attache.
Open Windows Explorer.
Type %localappdata% and press Enter.
Look for the Attache Software Australia Pty Ltd folder and rename it OLDAttache Software Australia Pty Ltd.
Reopen Attache and confirm that the error is gone. (A new Attache Software Australia Pty Ltd folder will get created).
📌Note: If you are using Attaché in our Cloud Hosted (CHS) environment, please raise a new case online and reference the title of this article, as you will not have access to the Attaché services and AppData folder.