MCTS recognizes that there is a path (i.e. "first_path_time" returns a nonzero value) but does not return any paths
Example output for such case:
{'status_code': 200,
'message': 'mcts.call_raw() successfully executed.',
'result': {'stats': {'total_iterations': 12,
'total_chemicals': 128,
'total_reactions': 126,
'total_templates': 126,
'total_paths': 0,
'first_path_time': 83.83375692367554,
'build_time': 83.84796118736267,
'path_time': 0.0016150474548339844},
'paths': [], ...
More details in no_paths_example