The default URL of the online Pentaho documentation changes with each release. When upgrading, you may need to update this URL parameter in the pentaho.xml file.
Navigate to the pentaho/server/pentaho-server/pentaho-solutions/system directory and open the pentaho.xml file with any text editor.
Modify the following <documentation-url> line and replace the previous documentation value with the current documentation value: <documentation-url>https://help.hitachivantara.com/Documentation/Pentaho/Data_Integration_and_Analytics/9.3</documentation-url>.