ODT export not enabled

I installed on server Saxon-HE (tried with version 10.3, 10 and 9.1.8). I put in wp-config.php define( 'PB_SAXON_COMMAND', '/usr/bin/java -jar /opt/saxon-he/saxon-he.jar' ); with right path.

When I try to export to ODT, there is no option, only warning: Some dependencies for MOBI, and OpenDocument exports could not be found. Please verify that you have completed the [installation instructions](http://docs.pressbooks.org/installation).

Is there something else to “enable” or install?