eclipse luna valid with connect iq plugin 2.1.5?

i have just done a fresh installation of luna on windows 10 x64, and i am not able of installing connectiq plugin.
i get a message that eclipse.core.expressions 3.5.0 is not available.
i am not very familiar with eclipse, but i have the feeling that this component should be already installed by default, but maybe the existing version is outdated?
i have realized that some of the screenshots in the starting guide show now mars edition.

EDIT: I have installed mars 5.2 and the error is not shown anymore. therefore it seems that now at least mars is required.