There seems to be a problem with the Dutch Calc Guide chapter 5 of LibreOffice 6.2.
If you open the odt-file only it shows #### and the pdf-version gives an error.
The guides are in the folder https://nextcloud.documentfoundation.org/apps/files/?dir=/LibreOffice%20Documentation/Dutch/Handleidingen/03%20Handleiding%20voor%20Calc/LibreOffice%206.2&fileid=127204 and then in the folders Archief, ODF-bestanden and Gepubliceerd. All the versions of that Guides have the same problem.
I have no idea what causes that problem.
Best regards,
Kees