Hi Andrea,
This has been discussed a lot in the community. As per the PAM flash player 14 supports for dashboard, but it seems lot of bugs to be face in using it. The recommend version would be to downgrade or the version 13 is good enough to do that.
Please go through the below link, where it has been explained lot briefer.
Dashboards issues with latest Adobe Flash Player 14.0
Hope this Helps!!!
--SumanT