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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at System.Data.SqlClient.SqlConnection.Open() at Microsoft.SharePoint.Utilities.SqlSession.OpenConnection() at Microsoft.SharePoint.Utilities.SqlSession.OpenConnection() at Microsoft.SharePoint.Utilities.SqlSession.OpenConnection() at Microsoft.SharePoint.Utilities.SqlSession.ExecuteReader(SqlCommand command, CommandBehavior behavior) at Microsoft.SharePoint.Administration.SPConfigurationDatabase.LookupHostHeaderSite(String hostHeader) at Microsoft.SharePoint.SPSite.LookupHostHeaderSite(Uri requestUri, SPFarm farm) at Microsoft.SharePoint.Administration.SPWebApplication.Lookup(SPFarm farm, Uri requestUri, Boolean fallbackToHttpContext, SPAlternateUrl& alternateUrl, SiteMapInfo& hostHeaderSiteInfo, Boolean& lookupRequiredContext) at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite, SPUserToken userToken) at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite) at Microsoft.SharePoint.WebControls.SPControl.SPWebEnsureSPControl(HttpContext context) at Microsoft.SharePoint.WebControls.SPControl.GetContextWeb(HttpContext context) at Microsoft.SharePoint.ApplicationRuntime.SPRequestModule.PostResolveRequestCacheHandler(Object oSender, EventArgs ea) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at Microsoft.SharePoint.Utilities.SqlSession.OpenConnection() at Microsoft.SharePoint.Utilities.SqlSession.ExecuteReader(SqlCommand command, CommandBehavior behavior) at Microsoft.SharePoint.Administration.SPConfigurationDatabase.LookupHostHeaderSite(String hostHeader) at Microsoft.SharePoint.SPSite.LookupHostHeaderSite(Uri requestUri, SPFarm farm) at Microsoft.SharePoint.Administration.SPWebApplication.Lookup(SPFarm farm, Uri requestUri, Boolean fallbackToHttpContext, SPAlternateUrl& alternateUrl, SiteMapInfo& hostHeaderSiteInfo, Boolean& lookupRequiredContext) at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite, SPUserToken userToken) at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite) at Microsoft.SharePoint.WebControls.SPControl.SPWebEnsureSPControl(HttpContext context) at Microsoft.SharePoint.WebControls.SPControl.GetContextWeb(HttpContext context) at Microsoft.SharePoint.ApplicationRuntime.SPRequestModule.PostResolveRequestCacheHandler(Object oSender, EventArgs ea) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at Microsoft.SharePoint.Utilities.SqlSession.OpenConnection() at Microsoft.SharePoint.Utilities.SqlSession.ExecuteReader(SqlCommand command, CommandBehavior behavior) at Microsoft.SharePoint.Administration.SPConfigurationDatabase.LookupHostHeaderSite(String hostHeader) at Microsoft.SharePoint.SPSite.LookupHostHeaderSite(Uri requestUri, SPFarm farm) at Microsoft.SharePoint.Administration.SPWebApplication.Lookup(SPFarm farm, Uri requestUri, Boolean fallbackToHttpContext, SPAlternateUrl& alternateUrl, SiteMapInfo& hostHeaderSiteInfo, Boolean& lookupRequiredContext) at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite, SPUserToken userToken) at Microsoft.SharePoint.Administration.SPNativeConfigurationProvider.LookupSite(String requestUrl, Int32 iisInstanceId, String& siteUrl, Int32& zone, Guid& appId, Guid& siteId, Guid& databaseId, String& databaseServer, String& databaseName, String& databaseUsername, String& databasePassword, Boolean& useHostHeaderForSiteName)