Which one specifically are you seeing? Depending on which error your seeing we will have to look at different things. However in either case there is probably something wrong with the managed account you configured and pushed via policy in the security settings document.
Is it this one
CLPEE2012E: An error occurred obtaining a security token to access the server. java.io.IOException
or this one:
CLPEE2012E: An error occurred obtaining a security token to access the server. java.net.UnknownHostException
Did you check that the managed account is configured and being passed down to the client?