At the beginning, I had this method too.
For everyone who wants to make a bypass too, it is really easy.
1. Start S4 League
2. Join a server
3. Suspend the process BEService.exe [You can do that with resmon.exe | Process Explorer]
4. Rejoin the server
5. Start S4Client_BE.exe with parameter 1
6. Close S4Client_BE.exe & BEService.exe fast
~~~
Good job, finally you have your bypass.

I also had this method. But after patch it's time to use the other method, if this got patched

(And no: It is not Login_Ack)