I’m encountering an issue when using the Npgsql library in my .NET Framework 4.6.1 project. Specifically, I’m getting the following exception when attempting to open an NpgsqlConnection:

Method 'DisposeAsync' in type 'Npgsql.NpgsqlBinaryExporter' from assembly 'Npgsql, Version=4.1.14.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' does not have an implementation.

Code Reference:

The error occurs at the point where I open the connection:

public static DataTable FetchMasterData()
{
    NpgsqlConnection npgsqlConn = new NpgsqlConnection(Connection.ConnectionStringPostgreSQL);

    DataTable classMasterTbl = new DataTable();
    string sqlQuery = string.Empty;
    NpgsqlCommand npgsqlCommand = null;

    try
    {
        sqlQuery = @"SELECT * FROM ClassMaster";
        npgsqlCommand = new NpgsqlCommand(sqlQuery, npgsqlConn);

        npgsqlConn.Open(); // Getting Error here

        NpgsqlDataAdapter dataAdapter = new NpgsqlDataAdapter(npgsqlCommand);
        dataAdapter.Fill(classMasterTbl);

        return classMasterTbl;
    }
    catch (Exception dalExce)
    {
        // Handled LoaderExceptions
    }
    finally
    {
        npgsqlCommand?.Dispose();
        npgsqlConn.Close();
    }
}

Target Framework: .NET Framework 4.6.1

Npgsql Version: 4.1.14.0

Database: PostgreSQL

Research:

From what I’ve gathered, the DisposeAsync method is part of the asynchronous disposal pattern introduced in .NET Core 3.0. However, since I’m using .NET Framework 4.6.1, this method is not natively supported. This seems to be causing the runtime exception.

Questions:

1. Is there a version of Npgsql that is fully compatible with .NET Framework 4.6.1 and does not require methods like DisposeAsync?
2. If not, what would be the recommended approach to resolve this issue while still targeting .NET Framework 4.6.1? Would upgrading the .NET Framework be the only viable option?

Any guidance or suggestions would be greatly appreciated!