nopSolutions/nopCommerce · critical · Exception

Unable to connect to the new database. Please try one more t

Error message

Unable to connect to the new database. Please try one more time

What it means

PostgreSqlDataProvider.CreateDatabase retries DatabaseExists() up to triesToConnect times (1s apart) after issuing CREATE DATABASE; if the new database is still not connectable on the final attempt it throws a bare Exception. On success it additionally installs the citext and pgcrypto extensions. This blocks the nopCommerce installer.

Source

Thrown at src/Libraries/Nop.Data/DataProviders/PostgreSqlDataProvider.cs:154

            var command = connection.CreateCommand();
            command.CommandText = query;
            command.Connection.Open();

            command.ExecuteNonQuery();
        }

        //try connect
        if (triesToConnect <= 0)
            return;

        //sometimes on slow servers (hosting) there could be situations when database requires some time to be created.
        //but we have already started creation of tables and sample data.
        //as a result there is an exception thrown and the installation process cannot continue.
        //that's why we are in a cycle of "triesToConnect" times trying to connect to a database with a delay of one second.
        for (var i = 0; i <= triesToConnect; i++)
        {
            if (i == triesToConnect)
                throw new Exception("Unable to connect to the new database. Please try one more time");

            if (!DatabaseExists())
                Thread.Sleep(1000);
            else
            {
                builder.Database = databaseName;
                using var connection = GetInternalDbConnection(builder.ConnectionString) as NpgsqlConnection;
                var command = connection.CreateCommand();
                command.CommandText = "CREATE EXTENSION IF NOT EXISTS citext; CREATE EXTENSION IF NOT EXISTS pgcrypto;";
                command.Connection.Open();
                command.ExecuteNonQuery();
                connection.ReloadTypes();

                break;
            }
        }
    }

View on GitHub (pinned to 64bdf2ff08)

Solutions

  1. Increase triesToConnect so the poll loop tolerates slower provisioning.
  2. Verify the PostgreSQL role has CREATEDB and CONNECT privileges and that citext/pgcrypto are available/installable.
  3. Confirm host, port 5432 reachability, and credentials; test an external psql connect first.
  4. Pre-create the database and the citext/pgcrypto extensions manually, then run installation.

Example fix

// before
dataProvider.CreateDatabase(dbName, triesToConnect: 5);

// after
dataProvider.CreateDatabase(dbName, triesToConnect: 30);
Defensive patterns

Strategy: retry

Validate before calling

// Pre-flight: confirm PostgreSQL reachable and role can connect
if (!dataProvider.DatabaseExists())
    throw new InvalidOperationException("Cannot reach PostgreSQL; check connection string and role privileges.");

Try / catch

try { dataProvider.CreateDatabase(dbName, triesToConnect: 30); }
catch (Exception ex) when (ex.Message.Contains("Unable to connect to the new database"))
{ /* verify role CREATEDB/CONNECT, citext/pgcrypto availability, port 5432, then retry */ }

Prevention

When it happens

Trigger: Installation calls dataProvider.CreateDatabase(databaseName, triesToConnect) against PostgreSQL where the server is slow to make the new database connectable, or where the role lacks permission to create/connect, within the retry budget.

Common situations: PostgreSQL on constrained hosting with provisioning lag; role without CREATEDB/CONNECT privileges so DatabaseExists always fails; missing citext/pgcrypto extensions and the role cannot CREATE EXTENSION; wrong host/port/firewall blocking 5432.

Related errors

AI-assisted analysis of nopSolutions/nopCommerce@64bdf2ff08 (2026-08-13). Data as JSON: /api/errors/93d0f9b0145e09e9. Report an issue: GitHub.