String indices must be integers in BertPreTrainedModel

Models
1

While training the model in text classification task, it kept saying this error, but since I ran this code few days ago , i am not understanding why it’s not working anymore

Epoch:   0%|          | 0/10 [00:02<?, ?it/s]
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-36-cdf49a404347> in <cell line: 1>()
----> 1 train(model=model, 
      2       criterion=criterion,
      3       optimizer=optimizer,
      4       train_loader=train_loader,
      5       val_loader=valid_loader,

3 frames
<ipython-input-30-e26e65f9e3c5> in train(model, criterion, optimizer, train_loader, val_loader, epochs, device)
      9             input_ids, attention_mask, labels = input_ids.to(device), attention_mask.to(device), labels.to(device)
     10 
---> 11             logits = model(input_ids=input_ids, attention_mask=attention_mask)
     12 
     13             loss = criterion(logits, labels)

/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py in _wrapped_call_impl(self, *args, **kwargs)
   1516             return self._compiled_call_impl(*args, **kwargs)  # type: ignore[misc]
   1517         else:
-> 1518             return self._call_impl(*args, **kwargs)
   1519 
   1520     def _call_impl(self, *args, **kwargs):

/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py in _call_impl(self, *args, **kwargs)
   1525                 or _global_backward_pre_hooks or _global_backward_hooks
   1526                 or _global_forward_hooks or _global_forward_pre_hooks):
-> 1527             return forward_call(*args, **kwargs)
   1528 
   1529         try:

<ipython-input-26-ca436c0e67a1> in forward(self, input_ids, attention_mask)
     10         reps, _ = self.bert(input_ids=input_ids, attention_mask=attention_mask)
     11         #Obtain the representations of [CLS] heads
---> 12         cls_reps = reps[:, 0]
     13         logits = self.cls_layer(cls_reps)
     14         return logits

TypeError: string indices must be integers

thanks in advance