How to solve the problems encountered during operation training?

[jiayinlala]

Traceback (most recent call last): File "C:\ProgramData\Anaconda3\lib\multiprocessing\process.py", line 315, in _bootstrap self.run() File "C:\ProgramData\Anaconda3\lib\multiprocessing\process.py", line 108, in run self._target(*self._args, **self._kwargs) File "C:\Users\xuptcs\Desktop\MADPL-master\learner.py", line 99, in sampler s = env.step_sys(next_s, next_a) File "C:\Users\xuptcs\Desktop\MADPL-master\controller.py", line 44, in step_sys current_s = self.update_belief_sys(s, sys_a) File "C:\Users\xuptcs\Desktop\MADPL-master\tracker.py", line 106, in update_belief_sys book_domain = entities[0]['ref'].split('-')[0] KeyError: 'ref'