Hi,
You need to navigate to your server installation files X:/Program Files/MTA San Andreas 1.3.1/server/mods/deathmatch/mtaserver.conf
Open that file in Notepad or something like that and press CTRL + F to find "ase" (without the ") change this line <ase>0</ase> from 0 to a 1 so it would look like this <ase>1</ase>