i have 2 sites running 8 exchange servers 2010. i install 4 servers in one site and assign 2 for CAS and 2 for mailbox .. migration working fine .. user can acess OWA .. only issue i have is in creating new mailbox through EAC .. it stuck with error

"Exception has been thrown by the target of an invocation"

for screenshot please visit below link.

http://social.technet.microsoft.com/Forums/en-US/exchangesvradmin/thread/34217947-97d5-4370-96dd-bd71f852a4ca/#f69133d6-3226-4af8-8999-7c169ba2750b