We're currently running Exchange 2007 and 2013 in coexistence as we prepare to transition fully to 2013. We have loaded a couple of test users into 2013 and all seems to work well other than one small issue with OWA. We can log in with their accounts and access mail and calendars, but when we click on "People" or "Tasks", the main windows loops "Loading" indefinitely. Does anybody have a thought as to how to resolve this? Thanks in advance!