An unexpected error occurred and your request couldn’t be handled.
Not able to compose new emails in OWA/Webmail.
While user access the webmail/OWA user getting an error “An unexpected error occurred and your request couldn’t be handled”
Due to the above error message user not able to access mailbox, Calendar, Task and Contacts in webmail.
1. When I checked the IIS settings in Client access server I found HTTP Redirect option were enabled and unchecked/disabled the option to resolve the issue.
2. Reset the IIS (iisreset /noforce).
3. Check the IIS binding option and make sure "All Assigned IP address" is selected.
Now user able to access the mailbox successfully.