I am upgrading from 2005 to 2008 r2. I have the very same exact issue/scenario as described in http://www.go4answers.com/Example/security-extension-report-manager-26934.aspx. I installed CU4 instead of CU3 as the link suggests. When go to the Report Manager url, I get to the UILogon.aspx page just fine to log on with good credentials, but after I enter Username and Password, I get the following message on the form itself: "Value cannot be null. Parameter name: uriString". I can get to Report Manager just fine if I logon to the Report Server first and leave it in IE, and then Invoke Report Manager. I think/hope I am missing a setting in a .config file somewhere, I just can't figure out which one. Mick

Hi Mick, I reproduced the issue as you mentioned before. It seems to be a known issue, and I used HTTP modules to fix the issue. The following feedback details the workaround: https://connect.microsoft.com/SQLServer/feedback/details/533197/sql-server-2008-r2-november-ctp-forms-authentication-not-working-in-ssrs?wa=wsignin1.0 If you have any more questions, please feel free to ask. Thanks, Jin ChenJin Chen - MSFT

Thank you Jin, I will work on creating the HTTP module on Monday when I am back at work and can get back into our Development environment and let you know how it works. Happy Thanksgiving to you if you celebrate it. MickMick

Hi Mick, Is there any update? Thanks, Jin ChenJin Chen - MSFT

Hi Jin, Yes, we decided to live with the problem for now, because we can get to Report Manager after navigating to the Report Server url, and IT personnel can do that to run Report Manager if they need to. Other corporate personnel and external users either get to the reports through web apps or need to run Report Builder, all of which go through the Web Service, and so far they all seem to work fine in the test environment after preliminary testing. Thank you for your help, MickMick