Hello Miquel,
it should work if you proceed as follows:
1. Open your XLSX file in Excel, choose "Save as" and save it as a "CSV UTF-8 (*.csv)"
2. Close the file (close Excel)
3. Copy the file to your DocuWare FTP subfolder "data" (ftp://ftp.docuware-online.de/.../data as described in the KBA article)
4. Create a new file connection in the DocuWare Administration
Check if you have set up all column types correctly (they have to match later on with the field types in your file cabinet (a file cabinet text filed must be defined as text here, numeric/decimal as numeric (with the correct subsettings) and date as date) - if your forget to check this or you do any mistakes here, it will not work, because you won't be able to define the matching field in the Autoindex configuration!
Check also, if your CSV-file has column headings in line 1. If so, define this here as well by changing the "Number of line with column heading" from 0 to 1 and also "Start extraction in line" from 1 to 2. Save the file connection and close the DocuWare Administration
5. Create a new Autoindex in the DocuWare Configuration in the correct file cabinet. The index data should be based on this file connection, and the matchcode section should contains all necessary fields which are important here
Best regards and good luck!
Frank