Msg 22004, Level 16, State 1, Line 0

Today I was working on Producing the Deadlock in My local Machine, hence I have enabled the trace flag globally ,I did the work and made the Deadlock situation,so I Planned to read SQL error log so I hit the command in an new query window(even I was not able to view in SSMS as well) ->Got the below error message:

Msg 22004, Level 16, State 1, Line 0
Failed to open loopback connection. Please see event log for more information.
Msg 22004, Level 16, State 1, Line 0
error log location not found

so to trouble shoot this one I have checked the below things(Note that the issue depends on the various reason & I have showed what caused in my case).
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1.Verified the SQL error log file exists in the proper path(Of course if the SQL error log path is in correct the SQL server Won't start up).

                             

2.Verified at the regsitry level of SQL log Path =>There is no issues at all.

3.verified at the Folder level permissions and Local administrators level =>No issues at all.

so as in the error it shows clearly that "Msg 22004, Level 16, State 1, Line 0,Failed to open loopback connection. Please see event log for more information.
Msg 22004, Level 16, State 1, Line 0
error log location not found"

So I moved to Event logs --Found some of the valuable informations as mentioned below-

Event Type:    Error
Event Source:    MSSQLSERVER
Event Category:    (2)
Event ID:    17052
Date:        02/01/2012
Time:        08:56:22
User:        N/A
Computer:    RAKUBERA
Description:
Severity: 16 Error:-1, OS: -1 [Microsoft][SQL Server Native Client 10.0]SQL Server Network Interfaces: Error getting enabled protocols list from registry [xFFFFFFFF].

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
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Event Type:    Error
Event Source:    MSSQLSERVER
Event Category:    (2)
Event ID:    17052
Date:        02/01/2012
Time:        08:57:56
User:        N/A
Computer:    RAKUBERA
Description:
Severity: 16 Error:-1, OS: -1 [Microsoft][SQL Server Native Client 10.0]SQL Server Network Interfaces: Error getting enabled protocols list from registry [xFFFFFFFF].

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
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Event Type:    Error
Event Source:    MSSQLSERVER
Event Category:    (2)
Event ID:    17052
Date:        02/01/2012
Time:        09:01:10
User:        N/A
Computer:    RAKUBERA
Description:
Severity: 16 Error:-1, OS: -1 [Microsoft][SQL Server Native Client 10.0]SQL Server Network Interfaces: Error getting enabled protocols list from registry [xFFFFFFFF].

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
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Event Type:    Error
Event Source:    MSSQLSERVER
Event Category:    (2)
Event ID:    17052
Date:        02/01/2012
Time:        09:01:40
User:        N/A
Computer:    RAKUBERA
Description:
Severity: 16 Error:-1, OS: -1 [Microsoft][SQL Server Native Client 10.0]SQL Server Network Interfaces: Error getting enabled protocols list from registry [xFFFFFFFF].

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
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In the SQL agent log I can see below messages:

2012-01-02 02:10:26 - ! [298] SQLServer Error: 65535, SQL Server Network Interfaces: Error getting enabled protocols list from registry [xFFFFFFFF]. [SQLSTATE 08001]
2012-01-02 02:10:26 - ! [165] ODBC Error: 0, Login timeout expired [SQLSTATE HYT00]
2012-01-02 02:10:26 - ! [298] SQLServer Error: 65535, A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online. [SQLSTATE 08001]
2012-01-02 02:10:26 - ! [000] Unable to connect to server 'RAKUBERA\SQL2K8'; SQLServerAgent cannot start


How ever there is no relations b/w the Agent and SQL Errorlog, How ever it provides valuable informations..

In My case is that ->I have SQL database engine local machine only (Obviously both Client & server is in same machine), I start checking the SQL Native clients via configuration Manger -->all the Protocols were disabled state , So I have checked the protocols of My SQL server 2008 what is the order of protocols :It was first shared memory,Named pipes then Tcp IP and VIA was in disbaled state...

so to resolve I went & enabled the protocols of Shared Memory then I executed the =>Exec xp_readerrorlog then Iam able to view the data in query window, also I was able to see in SSMS.

Bottom Lines
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1.Ensure that before performing understand the Logs properly, before peforming on Production check it in your test box.

2.Also the above issues arises in difference cases ==>The similar type of issue recevide in different situation --->see some of the below Links-What other person faced the similar issue and how he resolved(Thanks to them).

http://sqlserverpedia.com/blog/sql-server-bloggers/error-log-location-not-found/
http://www.pythian.com/news/27905/sql-serveropening-errorlogfailed-to-retrieve-data-for-this-request-microsoft-sqlserver-management-sdk-sfc/
http://www.sqlservercentral.com/Forums/Topic767980-146-1.aspx
http://ms-abhay.blogspot.com/2010/09/msg-22004-level-16-state-1-line-0.html