This error "HPF_PATH_GET: Invalid start/ target node(s)!". How do I check the entity speed per tick? I built a level that's slightly smaller than the "test" level I downloaded with your code and I'm calling up the level from the menu in my game as if it were one of my game's levels. It only has 2 regions and a total of 18 nodes between the 2 paths, and only one AI character. So it's a small level.
My game loads the player into the level, but before now, I hadn't included any NPC in the game. So I put one NPC in my test level and tried to make it so that he finds his way to whatever spot the player was standing when the "t" key was pressed. He should go to that spot even if the player has moved away from the placw. This is the code the AI is running:
Code:
action FollowPlayer()
{
	while(!player)
	wait(-1);
	
	vec_for_min(AIfeet, me); //assigning the lowest position of the model to the vector named "AIfeet"
	
	c_setminmax(my);
	vec_fill(my.min_x,-24);
	vec_fill(my.max_x,24);
	vec_set(PlayerTarget,my.x);
			
	my.skill10 = hpf_path_get_max_nodes(my);
	my.group = 2; // ignore other enemy units when doing pathfinding and visibility calculations (with IGNORE_PUSH)
	
	while(1)
	{
		if(key_t)
		vec_set(PlayerTarget, vector(player.x, player.y, player.z));
		
		my.red = 0;
	 	my.ambient = 0;
	 	my.lightrange = 0;
		
		if(!key_ins) hpf_region_get_target(temp,my,PlayerTarget,HPF_XYZ); //using insert key for dummy if statement
		else vec_set(temp, PlayerTarget);
		hpf_path_draw(my,COLOR_GREEN);
		temp.z = my.z;
		if(vec_dist(temp,my.x) > 16)
		{
			my.red = 100;
	 		my.ambient = 100;
	 		my.lightrange = 100;
	 		
			vec_diff(temp2,temp,my.x);
			vec_to_angle(temp,temp2);
			my.pan += ang(temp.x-my.pan)*0.25*time_step;
			result = c_move(me,vector(maxv(10-0.1*abs(ang(temp.x-my.pan)),0)*time_step,0,0), vector(0, 0, -AIdistancedown),IGNORE_PASSABLE | GLIDE);
			my.skill1 += result;
			my.skill1 %= 100;
			ent_animate(me,"run",my.skill1,ANM_CYCLE);
			
				
	 		//gravity codes		
	 		if(c_trace(my.x, vector(my.x,my.y,my.z-10000), IGNORE_ME|IGNORE_PASSABLE |USE_BOX) > 0)
	   	    AIdistancedown = my.z + AIfeet.z - target.z;
	     	else
	    	AIdistancedown = 0;
	   	
	    	if(AIdistancedown > 0)
	    	AIdistancedown = clamp(AIdistancedown, 0, accelerate(mygravity, 9.8, 0.1)); //0.1 is friction, accelerate "mygravity" by 9.8
	    	//clamp limits distance down to lower limit 0 and upper limit accelerate(mygravity, 9.8, 0.1)
	    	else
	    	{mygravity = 0; vec_set(AILastSolidGround,vector(my.x,my.y,my.z));}
	    	//if Mon is on ground, set gravity to zero and store position of mon on ground
		}
		
		var i;
		for(i = 1; i <= my.skill10; i++)
		{
			path_getnode(my,i,temp,NULL);
			if(vec_to_screen(temp,camera))
			{
				draw_text(str_for_num(NULL,i),temp.x-9,temp.y-9,vector(50,50,50));
				draw_text(str_for_num(NULL,i),temp.x-10,temp.y-10,COLOR_RED);
			}
		}
	
		
		wait(1);
	}
}


Sometimes it works perfectly. At random times, it gives this error "HPF_PATH_GET: Invalid start/ target node(s)!"
On the last few attempts, the whole game would hang without an error message. I can't find any pattern to the problem because the AI finds its way to certain spots perfectly sometimes, then crashes or gives an error at other times when asked to find its way to the same spot.