assert(npts >= num_neighbors) AssertionError

[Reeseee]

When I change the k_ration in agrs to generate multiple actions, AssertionError shows as:
Traceback (most recent call last):
File "/Users/xx/Downloads/DROO-master/mec/rlmodel/LDAS/main.py", line 211, in
train(args.train_iter, agent, env, evaluate,
File "/Users/xx/Downloads/DROO-master/mec/rlmodel/LDAS/main.py", line 87, in train
agent.select_action(observation, args=args),
File "/Users/xx/Downloads/DROO-master/mec/rlmodel/LDAS/wolp.py", line 326, in select_action
actions = self.action_space.search_point(proto_action, self.k_nearest_neighbors)[0]
File "/Users/katerina/Downloads/DROO-master/mec/rlmodel/LDAS/action_space.py", line 28, in search_point
search_res, _ = self._flann.nn_index(p_in, k)
File "/Users/xx/opt/anaconda3/envs/tensorflow/lib/python3.8/site-packages/pyflann/index.py", line 223, in nn_index
assert(npts >= num_neighbors)
AssertionError

What's the reason and how can I fix it?