SO- my previous post was deleted by someone about SharePoint not talking to TFS

Question

If you are going to delete this, please have the courtesy to let me know before doing so.
Our TFS SharePoint integration has ceased to work, and so far all the so called "fixes" have not worked to correct this. ON the TFS forum they are saying its a SharePoint issue. The databases are not corrupt according to my DBA without knowing
exactly where to look in more depth. This is not a unique issue - I see other postings with the same issue. What I'm not seeing a good solution. Most are VAGUE in how it was resolved. I'm frustrated beyond belief on this! 
We try to go to the website and we get this
Server Error in '/' Application.
Runtime Error
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed.
Details: To enable the details of this specific error message to be viewable on the local server machine, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application.
This <customErrors> tag should then have its "mode" attribute set to "RemoteOnly". To enable the details to be viewable on remote machines, please set "mode" to "Off".
Try to repair the connection and we get the following
  HTTP code 500: Internal Server Error
Connecting project portal site at http://HOSTNAME/sites/PROJECT/Setup (118 of 118)
[Error] Connection failed for project portal site athttp://HOSTNAME/sites/PROJECT/Setup: Please contact your administrator. There was an error contacting the server.
Technical information (for administrator):
  HTTP code 500: Internal Server Error
Event Debug log contains
 Message System.Data.SqlClient.SqlException (0x80131904): The DEFAULT_SCHEMA clause cannot be used with a Windows group or with principals mapped to certificates or asymmetric keys. ModifyExecRole account=OPENSCAN\OSSCM Group operation=1 Adding ...
checking if login exists checking if dbo checking if already in role OPENSCAN\OSSCM Group is in the role. noop Setting default schema to dbo Failed to set default schema at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection,
Action`1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler,
SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior
cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String
method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite)
at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at Microsoft.TeamFoundation.Framework.Server.TeamFoundationSqlResourceComponent.Execute(ExecuteType executeType, CommandBehavior behavior) ClientConnectionId:32f02e94-6375-4465-9f8b-2c8e894cc479 
Try to change or verify the Share Point Web Application Settings and get
TF255329: The following site could not be accessed: {HOSTNAME URL}. The server that you specified did not return the expected response. Either you have not installed the Team Foundation Extensions for Share Products (which we have - it
was working) or a firewall is blocking access..... Our IT person said there have been no firewall changes. 

Answer 1

Hi Retzcat,
I would like to do you the help. But same to Trevor, I don't have experiences on TFS integration.
Here, I would just focus on the error message:
The DEFAULT_SCHEMA clause cannot be used with a Windows group or with principals mapped to certificates or asymmetric keys
The error happens in:
In SQL Server, we have a login which is a Windows Group. It seems to be OPENSCAN\OSSCM in this case. Check from SQL Server Management Studio(SSMS), Server -> Security -> Logins, double-click OPENSCAN\OSSCM, in the coming window, the "Login Name"
should be account for a domain group.
Go to the WSS content database or the TFS database, Security -> Users, there should have OPENSCAN\OSSCM too.
Now, seems the code execute a TSQL script like this:
ALTER USER OPENSCAN\OSSCM WITH DEFAULT_SCHEMA = dbo;
As by design, we can assign default schema for windows group. The query fail.
Back to TFS integration, in this case, seems we are using a domain group as an account to configure the integration. Please try to change it to a domain user to fix the issue. For information on how to change the account, please go to TFS forum. Appreciate
for your understanding.
Thanks,
Jinchun Chen
Jinchun Chen(JC)
TechNet Community Support