Explanation:
Every document that is sent to DATEV is given a unique ID that only exists once in DATEV. If this document already exists in your database or has been uploaded to another one, you will receive this warning.
Solution:
Do you want to upload the documents to DATEV again because, for example, the wrong export method was used? Then these documents must be deleted in DATEV Unternehmen online and removed from the recycle bin.
Once the documents have been successfully deleted and removed from the recycle bin, you can perform the export again.