Hi - that message says that you are running 6.1. The current version of Rhino 6 is 6.17 with release candidates for 6.18 available. Please update your Rhino.
-wim
Hi Wim, don´t worry, I´ve just updated Rhino6 and everything works fine now. I thought I had to reinstall all plugins… but fortunately it is not the case. Thanks!