xtrafun was removed when amx updated to amx0.9.9
you can try this -
http://forums.alliedmods.net/showthread.php?t=33059
or
wait til the hero is recoded to work correctly
or
remove the line "#include<xtrafun>" at the top of the sma and see if it compiles as most heroes arent usually using it.
This is the last time I am stating this for you people that don't know how to search for answers.