tensor dont match problem

[gmy1234]

File "/Users/gmydl/opt/anaconda3/envs/deepke/lib/python3.8/site-packages/transformers/models/bert/modeling_bert.py", line 985, in forward
buffered_token_type_ids_expanded = buffered_token_type_ids.expand(batch_size, seq_length)
RuntimeError: The expanded size of the tensor (778) must match the existing size (512) at non-singleton dimension 1. Target sizes: [1, 778]. Tensor sizes: [1, 512]

你好 这个问题是因为什么？