Just recently, in a CRM 2013 SP1 UR 1 organisation we found that the CRM organisation just went down. Following was the screen when we try to hit CRM url:

When checking logs, found the following logs:

The initialization of the CRM authentication pipline has failed and all user requests to this CRM Server role computer will be denied.

CrmTrace encountered an error. Additional Info:Error in LoadDeploymentSettings [A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server)], Stack Trace :    at System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)

  at System.Environment.get_StackTrace()

   at Microsoft.Crm.CrmTraceSettings.Load(String traceDirectory)

   at Microsoft.Crm.CrmTrace.get_RefreshTrace()

   at Microsoft.Crm.CrmTrace.Write(Guid orgId, TraceCategory traceCategory, TraceLevel traceLevel, Int32 skipFrames, String format, Object[] args)

   at Microsoft.Crm.CrmTrace.TraceFormat(Guid orgId, TraceCategory traceCategory, TraceLevel traceLevel, String format, Object[] args)

   at Microsoft.Crm.Authentication.Claims.ClaimsUtility.InitializeApplication()

   at Microsoft.Crm.MainApplication.Application_OnStart()

   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)

   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)

   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

   at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)

   at System.Web.HttpApplication.InvokeMethodWithAssert(MethodInfo method, Int32 paramCount, Object eventSource, EventArgs eventArgs)

   at System.Web.HttpApplication.ProcessSpecialRequest(HttpContext context, MethodInfo method, Int32 paramCount, Object eventSource, EventArgs eventArgs, HttpSessionState session)

   at System.Web.HttpApplicationFactory.EnsureAppStartCalled(HttpContext context)

   at System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext context)

   at System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)

   at System.Web.Hosting.ISAPIRuntime.ProcessRequest

It seemed to be some issue with SQL service not being able to connect to CRM App server.

Error Resolution:

1. Go to SQL server —> Start –> all programs –> Microsoft SQL —> Configuration Tools —> SQL Server configuration Manager

2. In this expand SQL Server Network Configuration —> Protocols for MSSQLSERVER(if yours in on instance select that )—> Selecet Named Pipes–> enable it.

3. Restart sql service.

4. Next, on CRM server enable NET>TCP port sharing service(If already enabled restart it).

Hope it helps!