That picture doesn't give much to go on, but it looks like you've gone into Outlook Web App and then to Options, taking you to the Exchange Control Panel (ECP).
As a first measure (if you're not already), try it in Internet Explorer 7 or higher rather than some other browser or an older version of Internet Explorer.
Next, check all your Exchange services are running by running the Test-ServiceHealth
cmdlet and looking for any of your roles where the RequiredServicesRunning
property is False. If so, you'll get a list of services not running in the ServicesNotRunning
property. Start all of these with the cmdlet Start-Service
(i.e Start-Service MSExchangeAB
). You could always try bouncing IIS, just for good measure (iisreset /noforce
).
Are you able to update the signature from the shell? Try running Set-MailboxMessageConfiguration SomeMailbox -AutoAddSignature $true -SignatureHtml 'Testing signature from shell'
- that will enable the signature and populate it with a value (just to test it's not fundamentally broken). Refresh the ECP and see if that appears in your signature box.
Edit
You say you changed the port OWA is on - did you tell Exchange you did this by updating the internal and external URLs of OWA and ECP? This is under the Server Configuration => Client Access section in the Exchange management console.