I'm a new user trying Unity, and forgive me if this is a dumb question that can easily be solved with a single button, but I have been pulling my hair out trying to figure out why I keep getting these errors. Here is a screenshot:
UnityEngine.RuntimePlatform.OSXDashboardPlayer is obsolete
As the errors message said, the RuntimePlatform.WindowsWebPlayer is Obsolete, same as OSXWebPlayer and OSXDashBoardPlayer.
If the issue is caused by some third-party SDK(Plugin), you could try to update it to the latest version. Or not to use it if possible.