If you just installed Exchange 2013 and you have an Exchange 2010 mailbox you cannot access EAC you get the old ECP management
October 2, 2013Can't edit virtual machines once you upgrade to VMware 5.5 ESX and a virtual machine version 10
November 30, 2013If you are experiencing this issue it is a simple fix. You just need to download this DNE fix.
http://www.citrix.com/go/lp/dne.html
