I have seen many posts about this error when deleting or forwarding email, but none of the solutions seem to work.
For myself we are getting the error when trying to view email folders in OWA 2010 SP1. It is a clean install, not an upgrade.
The error is
An unexpected error occurred and your request couldn't be handled.
User host address:192.168.110.106
Ex Address: /0=First Organization/ou=Exchange Administrative Group
SMTP Address: user email address
OWA version: 184.108.40.206
Mailbox server: my server