Hi DKK01,
Welcome to our Community Forum! We appreciate the screenshots you've provided.
Based on the screenshots, you likely import your invoices to your application. Generally, this error message is often caused by the presence of pipe characters (|) in the invoice numbers (e.g., abc|123).
To resolve this, I recommend checking your invoices and removing any pipe characters from the invoice numbers. This should likely rectify the problem.
If the issue persists after making these changes, please provide the last 4 digits of your serial number. We'll investigate this matter further.
Should you need additional assistance or have other concerns, feel free to start a new thread in the forum.
If my response has answered your inquiry, please click "Accept as Solution" to assist other users find this information.
Thanks,
Genreve