Question

Hi I’m trying to use and understand Roles for the first time.
How can I resolve this? Do I need to add something to the WebConfig?

private static void CreateRoleIfNotExists(string role)
{
    if (!Roles.RoleExists(role)) // this line throws the error.
    {
        Roles.CreateRole(role);
    }  
}

Update, complete stacktrace inserted below:

[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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)]
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4856727
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194
System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) +4867325
System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +90
System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +374
System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +225
System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +189
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +4868451
System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +31
System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +431
System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +499
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +65
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +117
System.Data.SqlClient.SqlConnection.Open() +122
System.Web.DataAccess.SqlConnectionHolder.Open(HttpContext context, Boolean revertImpersonate) +87
System.Web.DataAccess.SqlConnectionHelper.GetConnection(String connectionString, Boolean revertImpersonation) +221
System.Web.Security.SqlRoleProvider.RoleExists(String roleName) +478
System.Web.Security.Roles.RoleExists(String roleName) +73
dk.certifikat.Global.CreateRoleIfNotExists(String role)

Answer 1

If you use the standard .net membership providers and roleproviders you need to setup the aspnetdb

this can be done by a command from the commandprompt

aspnet_regsql

this can be found in you .net framework directory.
If you did this. You need to provide the application with an connectionstring to the database where the aspnetdb is running.

more about this can be found here.