Well that is a weird bug.
I understand your primary concern is to have the bots installed as fast as possible, but mine is to understand why the script doesn't work
1.- Are you sure Front Line Force is installed correctly? (i.e. do you have a "frontline" folder in C:\Program Files\Steam\SteamApps\email\half-life ?)
2.- Are you running the script from the correct directory? (i.e. from C:\Program Files\Steam\SteamApps\email\half-life\HPB_bot\frontline ?)
3.- Is metamod already running in Front Line Force ?
If all is okay, try deleting the .PIF files that come with the scripts and try again.