I did what u said and ty for that because i forgot to import two files from SR_PROXY to media.pk2 but same error still happening "Billing server error occurred".
I have searched a lot about this and that is why I ask for help in this forum because I have not found much about this error and I don't know what to do or try anymore.
IIS is working fine: if i search 127.0.0.1:8090/test.asp it show me the date and time.
and if i search 127.0.0.1:8090/dbconnect.asp it show me a blank page. I read this is that IIS is working fine. (8090 because i tested 8080 and is not working but with 8090 it works).
SOLVED
If anyone have same problem just check this post
Download version 2.5.0