I am getting the error below while running install/default.aspx. This is a SQL Connection error; however, the "Test Connection" succeeded previously during the install. The error occurs during membership upgrade. Please note that I am using the default configuration settings for the membership. I know that the database connection has succeeded as tables have been created in my database.

I suspect this might be related to a limited number of connections allowed for SQLExpress; however, that is only a hunch.

The version is YAF-v1.9.4-RC1-BIN

The error:

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)

Web.config membership

The stack:

[SqlException (0x80131904): 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)]
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +5038006
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning() +234
System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity) +5049394
System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, SqlConnection owningObject) +129
System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, TimeoutTimer timeout) +239
System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, TimeoutTimer timeout, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +218
System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +232
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +185
System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +33
System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +524
System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject, Boolean& isNewConnection) +933
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +154
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +126
System.Data.SqlClient.SqlConnection.Open() +125
YAF.Classes.Data.YafDBConnManager.get_OpenDBConnection() +39
YAF.Classes.Data.YafDBAccess.ExecuteNonQuery(SqlCommand cmd, Boolean transaction) +78
YAF.Providers.Membership.DB.UpgradeMembership(Int32 previousVersion, Int32 newVersion) +180
YAF.Install._default.UpgradeDatabase(Boolean fullText) in c:\Ibex\Projects\YetAnotherForum\install\default.aspx.cs:1013
YAF.Install._default.Wizard_NextButtonClick(Object sender, WizardNavigationEventArgs e) in c:\Ibex\Projects\YetAnotherForum\install\default.aspx.cs:619
System.Web.UI.WebControls.Wizard.OnNextButtonClick(WizardNavigationEventArgs e) +108
System.Web.UI.WebControls.Wizard.OnBubbleEvent(Object source, EventArgs e) +416
System.Web.UI.WebControls.WizardChildTable.OnBubbleEvent(Object source, EventArgs args) +19
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) +118
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +167
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5563

I'll bet you changed your default DB provider during the installation (e.g. instead of "yafnet" you are using something else) and did not modify your provider configuration.

Check your connection strings and rename your provider connection string name appropriately.

If this doesn't make sense you to you, post your app.config and db.config files here (sans passwords).

I think they are fine but here they are. Perhaps you can see something

db.config

app.config