In our case we were able to browse the BAM Portal but BAM Portal was not able to consume out of the box BAM Mgmt Web Service. And we were getting following entry in the event viewer:

Event Type: Error
Event Source: Bam Web Service
Event Category: None
Event ID: 12033
Date: 20/06/2009
Time: 13:56:00
User: N/A
Computer: MyComputer
Description:
Referenced database 'BAMPrimaryImport' on server 'MyComputer' is not accessible. The error is:
System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.BizTalk.Bam.WebServices.AsyncResult.End(AsyncResult asyncResult)
at Microsoft.BizTalk.Bam.WebServices.Management.GetViewSummaryAsyncResult.End(IAsyncResult result)
at Microsoft.BizTalk.Bam.WebServices.Management.BamManagementService.GetViewSummaryForCurrentUser()

We enabled BAM traces. It contains following information:

06/20/2009 13:57:00 Microsoft.BizTalk.Bam.WebServices.Management.GetViewSummaryAsyncResult CompleteGetViewSummary Error Exception thrown
Source:
Microsoft.BizTalk.Bam.WebServices
Error messages:
Object reference not set to an instance of an object.
Call stack:
at Microsoft.BizTalk.Bam.WebServices.TraceHelper.ThrowHelperSoapException(XmlQualifiedName faultCode, Exception exception, Int32 eventId, String message)
at Microsoft.BizTalk.Bam.WebServices.SecurityHelper.CompareUsernames(String user1, String user2)
at Microsoft.BizTalk.Bam.WebServices.Management.GetViewSummaryAsyncResult.ReadCurrentUsersViews(SqlDataReader sqlReader, Boolean isDbo)
at Microsoft.BizTalk.Bam.WebServices.Management.GetViewSummaryAsyncResult.GetViewSummaryForDatabase()
at Microsoft.BizTalk.Bam.WebServices.Management.GetViewSummaryAsyncResult.CompleteGetViewSummary()

I came across this blog by Tiho, so we cross checked following points:

1. BAMPrimaryImportDB is running under a domain account.
2. SQL Server is running under Windows Authentication.
3. We were able to browse the BAM Mgmt Web Service directly and we can invoke the Web Methods without any issue.

Later, while looking at the list of users who has access to the view, we found that there is a user who no longer exist in the Active Directory, but has still access to the view. Once we removed that user from the access list of the view, everything started working properly!!! So we wonder how a user who is not even present in Active Directory can cause such a issue.

We took a dive in the code and found that when you browse to BAM portal, you will see the list of views for which you have the access. The job of filtering the views based on authorization is done by the BAM Mgmt WS. In order to do the authorization BAM will take a list of all the users/groups who has access to the view and then tries to compare it with the current user. The catch here is the way comparison is happening. It is not a a string comparison. We translate the username/group to its security identifiers (SID) and then do the comparison. And in our case it was failing when the username to SID conversion was happening, as the user was not present in AD.

Unfortunately, the behaviour is same in BizTalk 2009. Product team is working on this and we should see a fix soon.

You might see above warning message when you run MBV report on a BizTalk Server, where BizTalk DB is configured on a Windows SQL Cluster. It completely safe to ignore this warning message iff <Machine-1> and <Machine-2> are part of same cluster i.e. <Machine-1> and <Machine-2> are configured as two physical nodes of the cluster. I am assuming that MSDTC is configured as a cluster resource. However if <Machine-1> and <Machine-2> are NOT configured as a part of same cluster, then it is must to fix it, in order to run Distributed Transaction successfully.

Whenever there is a Distributed Transaction happens between two different physical machines a superior and subordinate relationship established between them, superior being the one who starts the transaction and subordinate being the one which will participate in the transaction. And we cannot flow the transaction to subordinates if they have same CID as superior. So we HAVE to make sure that we have unique CID corresponding to MSDTC resource. While working with cluster where you have MSDTC as a clustered resource, you can have only one MSDTC service running doesn't matter how many nodes you have in the cluster. So that makes it as only single MSDTC service between all the nodes and that's why they have same CID

How to check if two machines have same CID for MSDTC service and How to fix it?

1-      Open registry editor.

2-      Browse to HKCR\CID.

3-      You will see four keys under it.

4-      Each of these keys has the same tree structure and there is one sub-key called "Description".

5-      You need to go through all the Keys and search for the one which has "Description" as "MSDTC".

Note: The "Description" should be "MSDTC" only as shown below:

6-      You can follow the same steps on other interrogated machines; if they are same continue following rest of the steps to change the CID value for MSDTC.

7-      Browse to www.GuidGen.com

8-      Click on "Create new GUID".

9-      Copy the newly create GUID under "Your GUID"

10-   Rename the key with the sub-key "Description" as "MSDTC" with the newly created GUID. For e.g. in above snapshot I would rename "2e2a8d19-18e3-4df0-8306-938d43895b89".

11-   Once you renamed it, please restart "Distributed Transaction Co-ordinator" service from Services.msc.