Thanks for your help.
Now, it's ok with the install.
My installation is an upgrade from a previous version. When I activate the
plugin with selecting Maven 2 -> "Use Maven dependency management". Errors
are displayed which where not there with the previous release :
Build path contains duplicate entry:
../.m2/repository/org/osgi/osgi_R4_core/1.0/osgi_R4_core-1.0.jar' for
project 'mngtlib'
The error is only in Eclipse, when I use the Maven CLI the compilation is
ok :(