Server Error in ‘/RSinteract’ Application.

Could not load file or assembly ‘Microsoft.ReportingServices.Interfaces’ or one of its dependencies. An attempt was made to load a program with an incorrect format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.BadImageFormatException: Could not load file or assembly ‘Microsoft.ReportingServices.Interfaces’ or one of its dependencies. An attempt was made to load a program with an incorrect format.

Let me start by apologising for the lack of a post in the last week or so, I have been really busy with the new, improved version of RSinteract (sneak preview in the next couple of weeks, watch this space).

One of the issues we have experienced time and again with RSinteract is a scenario where the ReportServer/Database or Analysis services is on a different machine from RSinteract as demonstrated in the following diagram. The problem manifests itself as an authentication issue when Reporting Services tries to retreive information from the Database or Analysis server because Active Directory credentials expire after the first hop, in this case from RSinteract to Reporting Services.

Microsoft are calling this the “Double Hop” problem. The reason for Reporting Services’ and Analysis Services’ lack of integration out of the box is “in the interest of security”. Active Directory uses Kerberos under the hood which can be configured to pass credentials between web apps or not. To get this working with RSinteract or indeed any ASP.NET application you need to correctly configure Kerberos delegation.

I’m having trouble tracking down the steps for Reporting Services, the link I had has gone dead since I began writing this post

So here’s the steps to configure your Analysis Services (from Business Intelligence and Agile Development Blog):

1. Download and install the SetSPN utility (Either from the Windows Resource kit, or from http://www.microsoft.com/downloads/details.aspx?FamilyID=5fd831fd-ab77-46a3-9cfe-ff01d29e5c46&DisplayLang=en)
2. SETSPN is used to configure a “Service Principal Name”, which is required by Kerberos
3. Create a Service Principal Name (SPN) for the Analysis Services Instance (on the AS server)
4. (If AS is running as a domain account) setspn.exe –A MSOLAPSvc.3/
5. Configure Active Directory Settings
6. All users that are connecting to Analysis Services through the intermediate host need to be allowed to use Kerberos Delegation (”Account is sensitive and cannot be delegated” must be unchecked)
7. The “Account is trusted for delegation” setting must be checked for each user and each service account used in the process.
8. The “Trust computer for delegation” setting must be checked for each computer used in the process
9. Configure IIS Settings for the Virtual Directory hosting the application (or SharePoint site)
10. The Authentication must be set to “Integrated Windows Authentication” or “Basic Authentication”
11. The application protection level must be set to “High (Isolated)”
12. The impersonation level for COM+ must be set to “Delegate”
13. The COM+ application identity must be set to an account where “Account is trusted for delegation” is checked.
14. Connection strings must include SSPI=Kerberos
15. Connection strings CANNOT use IP Addresses

Here’s some more information pertaining to the bug:

• http://social.msdn.microsoft.com/forums/en-US/sqlreportingservices/thread/b8ba8546-76e8-46dc-a96e-bc61e847521f/
• http://www.sharepointblogs.com/kwanl/archive/2007/01/23/double-hop-asp-net-developers-beware.aspx

I’ll update this post as soon as I find the information for configuring SSRS.

UPDATE: Further information on alternative fixes has come to my attention via StackOverflow.

This new error has popped up since Microsoft released the update KB956391.

The update is for a vulnerability in the GDI+ DLL which allowed a malicious user to execute code on the client machine (good old! – ed). The fix uses ActiveX Killbits which is a setting that Internet Explorer checks for each ActiveX control. If the Killbits are set, IE refuses to load the control.

The update set the Killbits for the version of the RS Client Print ActiveX control which is used by the version 8.0.0.0 of the ReportViewer which is referenced by RSinteract (and Report Manager). Thus the printing will not work in either.

To fix Report Manager you need to apply the ReportViewer SP1 patch and the Security Update for SQL Server SP2 (KB954606). Once this is working again you can fix RSinteract.

To fix RSinteract you need to apply another Security Update for SQL Server SP2 (KB954607).

Let us know if this fix doesn’t work for you.