Pre-training: ValueError: You should supply an encoding or a list of encodings to this method that includes input_ids, but you provided []

Beginners
1

Hello,
I am following the tutorial here to pre-train a bert model and somehow I got the following errors:
ValueError: You should supply an encoding or a list of encodings to this method that includes input_ids, but you provided []

The code is very straightforward from the tutorial:

model = BertForMaskedLM.from_pretrained('bert-base-multilingual-uncased')
bert_tokenizer = BertTokenizerFast.from_pretrained("bert-base-multilingual-uncased")
streaming_dataset = load_dataset('text', data_files='./train.txt', streaming=True, split="train")

training_args = TrainingArguments(
    output_dir='/project/bert/model',
    per_device_train_batch_size=16,
    per_device_eval_batch_size=32,
    evaluation_strategy='steps',
    eval_steps=100,
    logging_steps=100,
    num_train_epochs=3,
    save_strategy='steps',
    save_steps=500,
    max_steps=1000,
)

data_collator = DataCollatorForLanguageModeling(
    tokenizer=bert_tokenizer,
    mlm=True,
    mlm_probability=0.2
)

trainer = Trainer(
    model=model,
    tokenizer=bert_tokenizer,
    args=training_args,
    data_collator=data_collator,
    train_dataset=streaming_dataset,
)

Does anyone have idea on the reason for this?