When simply applying the Update Rollup 1 for Exchange 2010, you might end up with a blank logon screen at your CAS servers when you want to reach OWA.
When opening up the details of the error message, the following text is shown:
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; WOW64; Trident/4.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.30729; .NET CLR 3.5.21022; .NET CLR 3.5.30729) Timestamp: Wed, 23 Dec 2009 15:34:46 UTC
Message: Syntax error Line: 1 Char: 1 Code: 0 URI: https://localhost/owa/14.0.682.1/scripts/premium/flogon.js
How to solve it?
Start an Administrative Exchange Management Shell
Type ii Exchange2010-KB976573-x64-en.msp
Close the Exchange Management Shell and finish the patch.
NB If you do not run the Exchange Management Shell as an Administrative prompt, you will get an error regarding a premature ending of the patch..