Why can't I connect to the Firebird database?

Question

firebird

Wrote the simplest code, the error occurs on the line fbc.Open();

FbConnectionStringBuilder csb = new FbConnectionStringBuilder
            {
                DataSource = "LOCALHOST",
                Charset = "WIN1251",
                Database = @"D:\Университет\ДЗ во время дистанционки\Языки\Task2.fdb",
                UserID = "SYSDBA",
                Password = "masterkey",
                ServerType = FbServerType.Default
            };
            FbConnection fbc = new FbConnection(csb.ToString());
            fbc.Open();
            FbDatabaseInfo fb_inf = new FbDatabaseInfo(fbc); //информация о БД
            fbc.Close();

Answer 1

I gave up and installed version 2.5
UPD1: Restarting the server can also help. (Turning off and on an application or service)

Answer 2

Maybe the firewall is blocking, turn it off.