Just a little correction here:
In Collect and Collect Earth we use an older version of Saiku from 2013 (2.6) that uses Mondrian 3!
The latest version of Saiku ( http://community.meteorite.bi/ ) is 3.7.4 3.6 and it uses Mondrian 4. Mondrian 4 has a completely different way to define a schema than 3, so that the cubes generated by Collect Earth will not be valid for this latest version.
If you want to use the cubes tat are generated by Collect/Collect Earth you will have to use the 2.6 Saiku version.