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Exchange 2010 Troubleshooting: Outlook Web Access (OWA) Error - Couldn't find a base theme

Scenario:

You install a new Exchange 2010 Client Access Server (CAS) and after a reboot all seems to be working. Outlook is connecting fine, but you open Outlook Web Access (OWA) and are presented with the following error:

  • Outlook Web App didn't initialize. If the problem continues, please contact your helpdesk. Couldn't find a base theme (folder name=base)

https://collaborationpro.com/wp-content/uploads/2017/06/OWAError1.png

Solution:

To fix the above error is not major. Launch the EMS (Exchange Management Shell) and navigate to:

  • C:\Program Files\Microsoft\Exchange Server\V14\Bin (Change the drive letter if your installation is on another drive)

Type in UpdateCAS and press the tab button to populate the command which is .\UpdateCAS.ps1

The following will show as per the screenshot below:

https://collaborationpro.com/wp-content/uploads/2017/06/OWAError2.png

Once done you should have a working OWA page:

https://collaborationpro.com/wp-content/uploads/2017/06/OWAError3.png