[Gammix]

Actually you got it wrong:

pawn Код:

#if !defined FILE_SERVERIP
    #error Please #define FILE_SERVERIP "127.0.0.1"
#endif

Should/Recommended to be like this:

pawn Код:

#if !defined FILE_SERVERIP
    #define FILE_SERVERIP "127.0.0.1"
#endif

So if user haven't defined, the include will run on its default value.