We are in the process of upgrading from Exchange 2007 to 2013. Exchange is installed on Server 2012 R2. We are the coexistence stage and cannot log into the EAC. We can get to the login screen but when you enter a username and password the screen blinks then clears the password field. No error message appears. If you put in the incorrect password a message will appear stating invalid username or password. We have not yet been able to log into the EAC successfully.
We have tried removing then rebuilding the ECP directory but the issue still remains. We have tried adding ecp?ExchClientVer=15 to the URL without success. We have also tried creating a new account that was a member of Organization Management group but that account couldn't log into the EAC either. There are no events in the event viewer that relate to these failed logins.
I'm really not sure what to go next so any help would be appreciated. Thank you.
Daniel Cumming