Solved by nielsr in post #7 
              
              
                Hi, 
looking at the files: Ayham/roberta_gpt2_summarization_cnn_dailymail at main 
It indeed looks like only the weights (pytorch_model.bin) and model configuration (config.json) are uploaded, but not the tokenizer files. 
You can upload the tokenizer files programmatically using the huggingface_hub …