Error loading a plugin - RhinoCommon mismatch

The object says all.
I tried loading the Arena plugin and the WIP 6.0.15314.10471, 10/11/2015 complains about a RhinoCommon mismatch and does not load the plugin.
I understood there is (or will be) a backward compatibility.
Thanks in advance,

Hi Max- no - V5 plug-ins will not work in V6.


I misunderstood.
Best regards,