Situation
You have started an export with Rechnungsdatenservice 1.0. The export of one or more documents fails with the error 'Invalid file format'.
Cause
One or more documents were uploaded in a file format that is not supported by DATEV.
Allowed file formats: BMP, GIF, JPEG, JPG, PNG, TIF, TIFF.
Other files: CSV, DOC, DOCX, DTA, MSG, ODS, ODT, PDF, PK7, PKCS7, RTF, TXT, XLS, XLSX, XML
Which is odd, since we actually only allow PDF files in Candis. So how could you upload something that is not a PDF? 🤔 We'll take a look at that.
Resolution
Download the affected document once and save it as a PDF.
You can delete the faulty document now.
Then upload the PDF document and send it again for approval.
Click here for the official DATEV documentation for error #DCO01015 (in German).