You did not show how you create your model in your post, so no one can help you debug the problem.
Form the error message, it looks like you used torch.save to save your whole model (and not the weights), which is not recommended at all because when the model changes (like it did between 4.10 and 4.11) you then can’t reload it directly with torch.load.
Our advice is to always use save_pretrained/from_pretrained to save/load your models or if it’s not possible, to save the weights (model.state_dict) with torch.save and then reload them with model.load_state_dict, as this will works across different versions of the models.