MTP layer 45 weights are missing from the checkpoint

#1
by colabbear - opened

Hi,

I noticed that the MTP / NextN weights appear to be missing from the RedHatAI/GLM-5.3-Flash-NVFP4 checkpoint.

The original zai-org/GLM-5.3-Flash configuration indicates that the model has one NextN prediction layer:

"num_hidden_layers": 45,
"num_nextn_predict_layers": 1

Therefore, the MTP layer is expected to be stored as layer 45.

However, after checking model.safetensors.index.json in this repository, I could not find any tensors corresponding to layer 45 (model.layers.45.* / equivalent names).

When attempting to run the model with vLLM MTP speculative decoding enabled, vLLM fails during model loading with:

ValueError: MTP speculative decoding layer 45 weights missing from checkpoint.

For example, this happens when using an MTP speculative decoding configuration such as:

--speculative-config '{"method":"mtp","num_speculative_tokens":4}'

Without MTP speculative decoding enabled, the model can proceed without trying to load the missing MTP layer.

Could you clarify whether:

  1. the MTP / NextN layer was intentionally excluded during NVFP4 quantization/conversion, or
  2. the layer was unintentionally dropped during the conversion/save process?

If MTP is intentionally unsupported by this checkpoint, it may also be helpful to mention this limitation in the model card, since the inherited model configuration still indicates num_nextn_predict_layers: 1.

Thanks!

Red Hat AI org

Thank you for flagging! Working on an update

Red Hat AI org

@colabbear Thank you for calling this out. The checkpoint has been updated.

dsikka changed discussion status to closed

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