Hello Exchange experts,
We’re having a bit of an issue:
At the company I work for, we’ve decided to upgrade our Exchange 2010 DAG cluster from service pack 1 to service pack 2 due to a series of strange issues we are having. This upgrade process itself has caused some issues that we’re trying to solve.
The DAG consists of two (CAS & Hub Transport) servers and 2 MailDB servers running on Windows Server 2008 r2.
We started by upgrading the first of our two CAS servers, which caused a few issues, first we had problems with http -> https redirection, because the default website was changed to require ssl.
After this was solved, people were unable to log onto the OWA, which was solved by changing requireSSL in the following line in web.config to false.
<httpCookies httpOnlyCookies="false" requireSSL="false" domain=""/>
After applying this fix, our users were able to log on, and view their email, but when they try certain things they encounter an error, which says the following “An unexpected error occurred and your request couldn't be handled.”.
This happens when:
1) They try to create a new email, or reply to an existing email, and the fields “To:” or “CC:” are activated. That means there is no problem writing text, but the To field cannot be validated, and the mail cannot be sent.
If I press OK to hide the error, I can fill out the “To:” field, but when I then try to send the email the following pops up:
“You need to choose a recipient before this message can be sent.” And underneath that the same error reappears: “An unexpected error occurred and your request couldn't be handled.”.
2) Accessing Deleted emails causes the error to show up as soon as I enter the Deleted Emails folder. If I click OK, the error shows up every time I change to a different email.
3) Similarly for Sent items.
4) Curiously, NOT for the Inbox. I can browse those mails fine.
So the situation right now is that we have one SP2 CAS server that doesn’t work fully, and one SP1 CAS server that works fine, and we’re reluctant to upgrade the other one until the first one is fully functional.
We use a load balancer to switch between them, and have currently disabled the SP2 CAS server in the loadbalancer.