Outlook Web Access on Exchange Server 2007 may stop working after an Update Rollup is applied. Users who connect to OWA may receive a browser script error or a blank page with a URL of:
This problem can be caused by either of these conditions:
The Update Rollup was applied while the %systemdrive%\ExchangeSetupLogs folder was missing.
Replace or restore the ExchangeSetupLogs folder and run the Update Rollup again.
The Update Rollup was applied while IIS services were stopped or disabled. This will be apparent when you inspect the %systemdrive%\ExchangeSetupLogs\UpdateOwa.log file and find entries with the following text:
Getting all Exchange 2007 OWA Virtual Directories
There are no Exchange 2007 OWA Virtual Directories. Aborting.
Enable and start the IIS services (which are required for the Client Access Server role) and run the Update Rollup again.