C # crashes “Attribute does not exist” [closed]

I can not deal with this problem. The program falls with an error: the отношение "USERS" не существует even though the given table exists in the database and the query inserted into the SQL manager is successfully executed.

What could be the problem?

  public void selectDataForSync() //data from PG that whould be insert in SQLLITE { UserData ud; List<UserData> uds = new List<UserData>(); NpgsqlConnection conn = new NpgsqlConnection("Server=127.0.0.1;Port=5432;User Id=" + config.PGLogin + ";" + "Password=" + config.PGPass + ";"); conn.Open(); string SQLrequest = @"SELECT guid, username, ""FL"", id, userblob FROM ""USERS"" WHERE ""FL""=10;"; Console.WriteLine(SQLrequest); NpgsqlCommand command = new NpgsqlCommand(SQLrequest, conn); try { NpgsqlDataReader dr = command.ExecuteReader(); // here exception while (dr.Read()) { // UserData ud = new UserData(); ud.id = Int32.Parse(dr[0].ToString()); ud.guid = (dr[1].ToString()); ud.name = (dr[2].ToString()); ud.userblob = (byte[])dr[3]; // uds.Add(ud); //File.WriteAllBytes("outputimg.jpg", ud.userblob); //Console.ReadKey(); sqllite.insertDataFromPGToSQLLite(ud); } dr.Dispose(); // releases conenction } catch (Exception e) { Console.WriteLine("SelectDataForSync function"); Console.WriteLine(e.Message); } finally { conn.Close(); } } 

I tried to specify the schema - it did not help: string SQLrequest = @"SELECT guid, username, ""FL"", id, userblob FROM public.""USERS"" WHERE ""FL""=10;";