reference_latent in WanVideo Context Options causes device mismatch error (CPU vs CUDA)

[ansorre]

Description

When using reference_latent in WanVideoContextOptions, the sampler crashes with a device mismatch error during the torch.cat operation at line 1709 in nodes_sampler.py.

Error

RuntimeError: Expected all tensors to be on the same device, but found at least two devices, cpu and cuda:0! (when checking argument for argument tensors in method wrapper_CUDA_cat)

Traceback

File "...\nodes_sampler.py", line 1709, in process
    partial_img_emb[:, 0] = torch.cat([image_cond[:4, 0], new_init_image], dim=0)

Cause

At line 1707-1709, new_init_image is moved to intermediate_device, but image_cond may be on a different device (e.g., cuda:0). This causes the torch.cat to fail.

Suggested Fix

Line 1709, change:

partial_img_emb[:, 0] = torch.cat([image_cond[:4, 0], new_init_image], dim=0)

To:

partial_img_emb[:, 0] = torch.cat([image_cond[:4, 0], new_init_image.to(image_cond.device)], dim=0)

This ensures new_init_image is always on the same device as image_cond.

Environment

• ComfyUI-WanVideoWrapper (latest)
• Windows 11
• Dual RTX GPUs

[tuolaku]

the same issue