Instance problem

[Instance problem]

I'm updating an old script to hercules format. I'm running into a problem as the instance isn't created. Snippet below:

set .@md_name$,"Faceworm's Nest";
set .@party_id,getcharid(1);
set .@instance, instance_create(.@md_name$, getcharid(1));
debugmes "InstanceID: " + .@instance;
if (.@instance < 0) 
{
  if(.@instance == -3)
  {
	dispbottom "Memorial Dungeon, '"+.@md_name$+"' is already in progress.",0xFFFFFF;
  }
  else
  {
	mes "[Magic Scholar]";
	mes "Opps, my hands are slip off. It is required to activate the craks again.";
	close;
  }
}
debugmes "Instance Map " + instance_attachmap("1@face", .@instance);
if( instance_attachmap("1@face", .@instance) == "" )
{
	mes "[Magic Scholar]";
	mes "Opps, my hands are slip off. It is required to activate the craks again.";
	instance_destroy(.@instance);
	close;
}
instance_init(.@instance);

close;

The instance Id gave me 0 so unless that is not valid, I don't know what went wrong. Did I forget to do something?