VAE and latent channel mismatch: verify the exact variant, not just its family name

Symptoms and scope

An unexpected channel count or latent dimension calls for checking the model, VAE and latent-construction nodes together. Image and video latents do not all share the same structure.

Error fragments for search; IDs, values and filenames may vary:

expected input
channels
size of tensor

Source-supported context

Official model troubleshooting includes channel-count conflicts. Wan 2.2 documentation uses different VAE configurations for the 5B TI2V and 14B routes, so the family label alone does not justify substitution. Source 1 Source 2

Cases to distinguish

1. The VAE belongs to another model or variant.

2. An image, video or cross-family encoded latent is connected to an incompatible sampler/model.

3. An older template's dimensions, frames or specialized latent node has the same interface type but a different internal layout.

Diagnostic sequence

The sequence below is an editorial procedure based on the cited context, not a diagnosis already confirmed for your environment.

Step 1. Record expected and actual dimensions and identify whether encoding, sampling or decoding failed.

Step 2. Check the exact variant's official template for diffusion, VAE and latent-node choices.

Step 3. Restore its original encode–sample–decode chain, removing intermediate latents copied from other workflows. If the template and model permit a smaller image or shorter clip, test one supported reduction at a time.

Step 4. If template file instructions disagree, retain both URLs and versions and mark the relationship as unresolved instead of choosing the newest-looking filename.

Completion check

The matched chain passes sampling and decoding; add back only supported dimensions and optional controls after successful saving.

Limitations and cautions

Zero-padding, cropping channels or adjusting width/height does not generally fix architecture differences. No Wan variant or GPU capacity has been runtime-tested here.

Original sources

• ComfyUI model troubleshooting — original record checked 2026-09-21.
• Wan2.2 native workflows — original record checked 2026-09-21.

Localization prepared: 2026-09-22. The source-check dates above were inherited from the existing article; this translation does not claim they were all rechecked today. No GPU run, minimum-memory measurement or runtime guarantee is supplied.

Related troubleshooting and guides

• Wan 2.2 5B versus 14B: match the task, model stages and VAE
• VAE out of memory after sampling finishes: diagnose decoding separately
• mat1 and mat2 shapes cannot be multiplied: inspect the model component chain