AttributeError when training data

Dear developer, I get an error when training data:

AttributeError: Can't get attribute 'RNA_SS_data' on <module '__mp_main__' from 'D:\\大四\\上学期\\机器学习及其在化学中的应用\\大作业\\workdir\\ufold_train.py'>

The file related to 'mp_main' is "C:\Users\fly\anaconda3\lib\multiprocessing\spawn.py", it seems like a multiprocessing error, could you please help me with this problem? Thank you!