Sometime the Exchange roll up update may break the OWA

How to fix,

Run the Exchange Management Shell

Remove-OwaVirtualDirectory “owa (Default Web Site)”

Then recreate the owa with

New-OwaVirtualDirectory -OwaVersion “Exchange2007″ -Name “owa (Default Web Site)”

***It may failed the first time to recreate the OWA, restart the IIS services and then try the command again.

If our solution works, please donate and support our operation.