CLR20r3 - Unable to launch Report Builder 1.0

Hi all,

Need some help here.

When I double click on C:\Program Files\Microsoft SQL Server\MSRS10_50.MSSQLSERVER\Reporting Services\ReportServer\ReportBuilder\ReportBuilder.application

I receive the following error. I used to be able to run Report Builder 1.0 manually this way. My User mentioned that he recently changed the Server Administrator's password and unable to launch Report Builder.

SQL 2008R2

Description:
  Stopped working

Problem signature:
  Problem Event Name: CLR20r3
  Problem Signature 01: reportbuilder.exe
  Problem Signature 02: 10.50.1600.1
  Problem Signature 03: 4bb67768
  Problem Signature 04: ReportBuilder
  Problem Signature 05: 10.0.0.0
  Problem Signature 06: 4bb67768
  Problem Signature 07: 59c7
  Problem Signature 08: b
  Problem Signature 09: System.NullReferenceException
  OS Version: 6.1.7601.2.1.0.272.7
  Locale ID: 18441

Any help is greatly appreciated!

Thanks!