TypeError: LTXVImgToVideo.generate() got an unexpected keyword argument 'strength'

[CGMikeG]

Expected Behavior

Here is what VSCode copilot thinks
Great question! You do have strength in your generate method for LTXVImgToVideoAdvanced, but the error is about the method you are calling inside it:

return nodes_lt.LTXVImgToVideo().generate(
positive=positive,
negative=negative,
vae=vae,
image=image,
width=width,
height=height,
length=length,
batch_size=batch_size,
strength=strength, # <-- This is the problem
)

Here, you are calling the generate method of LTXVImgToVideo from nodes_lt (not your own class), and that method does not accept a strength argument.

Why does this happen?
Your own generate method accepts strength—that's fine.
But you are passing strength to another class's generate method (LTXVImgToVideo in nodes_lt), and that method does not have strength in its parameters.
How to fix?
You need to add strength to the generate method of LTXVImgToVideo in the comfy_extras/nodes_lt.py file (or wherever it is defined), like this:

class LTXVImgToVideo:
def generate(
self,
positive,
negative,
vae,
image,
width,
height,
length,
batch_size,
strength=None, # <-- Add this
):
# ...existing code...

Or, if you don't want to use strength, you can just add it with a default value and ignore it.

---

Unfortunately, above solution didn't fix the issue. :(

Actual Behavior

VAE load device: cuda:0, offload device: cpu, dtype: torch.bfloat16
gguf qtypes: F32 (728), BF16 (7), Q4_K (336), Q6_K (144)
model weight dtype torch.bfloat16, manual cast: None
model_type FLUX
CLIP/text encoder model load device: cuda:0, offload device: cpu, current: cpu, dtype: torch.float16
Requested to load MochiTEModel_
loaded completely 9822.8 9083.38671875 True
Using preset: 13b Dynamic
Skip steps sigma threshold: 0.997
Cfg star rescale: True
Sigma list: [1.0, 0.9933, 0.985, 0.9767, 0.9008, 0.618]
Cfg list: [1, 6, 8, 6, 1, 1]
Stg scale list: [0, 4, 4, 4, 2, 1]
Stg rescale list: [1, 0.5, 0.5, 1, 1, 1]
Stg layers indices list: [[11, 25, 35, 39], [22, 35, 39], [28], [28], [28], [28]]
optional_cond_images shape torch.Size([1, 512, 768, 3])
!!! Exception during processing !!! LTXVImgToVideo.generate() got an unexpected keyword argument 'strength'
Traceback (most recent call last):
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 347, in execute
output_data, output_ui, has_subgraph = get_output_data(obj, input_data_all, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb)
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 222, in get_output_data
return_values = _map_node_over_list(obj, input_data_all, obj.FUNCTION, allow_interrupt=True, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb)
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 194, in _map_node_over_list
process_inputs(input_dict, i)
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 183, in process_inputs
results.append(getattr(obj, func)(**inputs))
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\custom_nodes\ComfyUI-LTXVideo\easy_samplers.py", line 127, in sample
) = LTXVImgToVideo().generate(
TypeError: LTXVImgToVideo.generate() got an unexpected keyword argument 'strength'

Steps to Reproduce

Running workflow from

https://huggingface.co/wsbagnsv1/ltxv-13b-0.9.7-dev-GGUF/tree/main

exampleworkflow_I2V.json

Debug Logs

VAE load device: cuda:0, offload device: cpu, dtype: torch.bfloat16
gguf qtypes: F32 (728), BF16 (7), Q4_K (336), Q6_K (144)
model weight dtype torch.bfloat16, manual cast: None
model_type FLUX
CLIP/text encoder model load device: cuda:0, offload device: cpu, current: cpu, dtype: torch.float16
Requested to load MochiTEModel_
loaded completely 9822.8 9083.38671875 True
Using preset: 13b Dynamic
Skip steps sigma threshold: 0.997
Cfg star rescale: True
Sigma list: [1.0, 0.9933, 0.985, 0.9767, 0.9008, 0.618]
Cfg list: [1, 6, 8, 6, 1, 1]
Stg scale list: [0, 4, 4, 4, 2, 1]
Stg rescale list: [1, 0.5, 0.5, 1, 1, 1]
Stg layers indices list: [[11, 25, 35, 39], [22, 35, 39], [28], [28], [28], [28]]
optional_cond_images shape torch.Size([1, 512, 768, 3])
!!! Exception during processing !!! LTXVImgToVideo.generate() got an unexpected keyword argument 'strength'
Traceback (most recent call last):
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 347, in execute
output_data, output_ui, has_subgraph = get_output_data(obj, input_data_all, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb)
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 222, in get_output_data
return_values = _map_node_over_list(obj, input_data_all, obj.FUNCTION, allow_interrupt=True, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb)
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 194, in _map_node_over_list
process_inputs(input_dict, i)
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\execution.py", line 183, in process_inputs
results.append(getattr(obj, func)(**inputs))
File "F:\COMFY\ComfyUI_windows_portable\ComfyUI\custom_nodes\ComfyUI-LTXVideo\easy_samplers.py", line 127, in sample
) = LTXVImgToVideo().generate(
TypeError: LTXVImgToVideo.generate() got an unexpected keyword argument 'strength'

Other

No response

[agustincaniglia]

getting the same error, using kijai's model

[DarkAlchy]

Alright, I had this same error then I updated all and it ceased. I then started over with an older comfyui because this model just does not work for me. At best I get a static image which is why I started over twice. Once was just a new install all the second is the one I rolled back comfy and just installed the manager and the three packs this workflow used. BINGO, that error returned. If I update comfy the error will go away for sure, but this ltxv 0.9.7 will do nothing for me. Not sure why, but I am honestly fed up with spending two 12 hour days trying to get it to work. I give, and will just delete ltxv and go back to wan.

TL;DR Update ComfyUI and the error should go away, as it did me when I updated (the one I used was only two days prior when I originally updated that did away with this error).

[MrBerense1]

So this worked for me thank you DarkAlchy. Updated to the latest Comfyui 3.34... couldnt update from the cmd or comfyui manager so downloaded a new comfyui then updated to the latest version then got the LTX model and workflow now it works.

[anisboukhris]

had the same problem and i found someone on reddit that said simply just try changing optional_cond_indices to 1 in base sampler node and see if that works. because it did work for me so i though of sharing this too

[BrawnyAi]

It works but it shows the video like this.

[DarkAlchy]

Means it isn't really working as I had this at first until I updated everything. iow, rip venv...reinstall venv, then pip install -r requirements.txt. If you are on that portable thing I can't help (or worse the .exe thing).

[aklevecz]

Update ComfyUI.

LTXVImgToVideo is apart of comfy_extras so if your ComfyUI is behind then it is missing the parameter passed through the LTXBaseSampler

[phazei]

@aklevecz I'm using the latest version of comfy, updated recently. I'm getting this on the 🅛🅣🅧 LTXV Img To Video Advanced node specifically in the mixed multiscale workflow from the "Browse Templates"

@BrawnyAi that's a totally different unrelated issue. Your settings are off, I've gotten that exact thing before when my "shifts" were wrong, but numerous things can cause it, I don't know more.

Also should be linked:
Lightricks/ComfyUI-LTXVideo#190
Lightricks/ComfyUI-LTXVideo#198

[aklevecz]

@phazei if you're having the same error complaining about strength missing from the generate for 🅛🅣🅧 LTXV Img To Video Advanced I would still try updating Comfy and try restarting everything. It appears to be referencing the same thing as the Base Sampler.

I was able to run the Mixed Multiscale workflow right now and I was getting the strength error earlier before I updated. It took me a few tries of updating and restarting things, as Comfy sometimes does. Sorry I don't remember the exact order that refreshed everything. This is the first time I've run the new LTX stuff that was released recently.