Cannot create image to video.

[bob80817-dev]

All models are downloaded. When I try to create image to video I have two issues I cannot get past.

• flash attention is not installed in ComfyUI's Python — video generation runs ~4× slower without it. prebuilt wheels · pick the file matching your torch/CUDA/Python, pip install it into ComfyUI's Python, restart ComfyUI

• Install Vhs_VideoCombine

I'm new at this, so any help is appreciated. The option to download and install VHS does not work. A one second cmd prompt pops up and disappears. The option to continue with a .webp only creats a still image, not video. The prebuilt wheels option leads to a page , that to my understanding, is not build into Windows 11 and needs to be compiled.

I have a Nividia Geforce RTX 5070Ti. I forgot how to find which cuda version I have. Windows 11 Pro.

Any ideas?

[PurpleDoubleD]

hey bob, welcome, and thanks for the detail. let's get you a video.

first, the flash attention message is optional, it only makes video faster and isn't required, so ignore it for now, and no, you don't need to compile anything.

the real blocker is vhs_videocombine (the node that outputs an actual .mp4). that install step shells out to git and then pip, and a cmd window flashing and closing usually means git isn't found. can you open a terminal, run git --version, and tell me what it says? if that errors, install git for windows, restart lu, and try again. also: right after the flash, does lu show a red error line under the generate button? paste me that text if so. and what's your lu version (bottom-right of the app)?

the ".webp came out as a still" part shouldn't happen even without vhs, so once we get the node in i'll make sure you get real motion out of it.

[bob80817-dev]

Thank you for responding.

git version 2.55.0.windows.1

lu : v2.5.6 It was the previous version, but once I opened the app today it updated.

Attached is a screencap of me trying to install VHS from Github.

• "the ".webp came out as a still" part shouldn't happen" - that was on me. I opened it with Firefox and it played. So that bit is solved.

[bob80817-dev]

Just tried to install it again and received the same error:

C:\Users\Admin>gh repo clone Kosinkadink/ComfyUI-VideoHelperSuite
fatal: destination path 'ComfyUI-VideoHelperSuite' already exists and is not an empty directory.
failed to run git: exit status 128

It look like it cannot install because it already is? I'm new to all of this, so is there a way to uninstall it so that I may try to reinstall it?

[bob80817-dev]

Also, is response to "also: right after the flash, does lu show a red error line under the generate button?" No, it proceeds to create the video but only outputs the .webp.

[bob80817-dev]

This is after I chose to Install and continue. Again, small box flashes for one second and the process continues, but only outputs .webp

[bob80817-dev]

I recorded the screen during the process.

2026-07-01_11-34-54.mp4

[bob80817-dev]

As you as I have your attention, gow do I increase the length of the output? The webp generated is about 3 seconds long. Hard to tell without the ability to play it with VLC.

[bob80817-dev]

I found one that will do that, but I get this error:

Failed to submit: ComfyUI rejected workflow: Node 'easy cleanGpuUsed' not found. The custom node may not be installed.

Just out of curiosity how do we install nodes on this? I saw that the Comfy desktop has a mode management button, but I'm not seeing it on this version.

[bob80817-dev]

I still have not been able to solve the VHS issue.

[bob80817-dev]

[PurpleDoubleD]

no fix to claim on this one yet, being straight with you. to get further i need the comfyui side of the story, the console output from right after the error, that is the black window that runs alongside comfyui, or the log file inside your comfyui folder. the app can only say missing or not missing, the console says why. paste that here and we dig into the real error instead of guessing.

[bob80817-dev]

There is no fix. Noone helped me out, so I uninstalled it. Couple days later I reinstalled it on my C drive as opposed to an external, and it worked. All of your downloads needed for this thing have a habit of timing out.

So, in short: it doesn't play nice when installed on an external HDD, and you have to fight to get stuff downloaded.

[PurpleDoubleD]

saw you got it working from drive c after the reinstall, sorry the external drive run burned you out. that was on us for being too slow with an answer. your reports have fixed more bugs in this app than anyone else. if the external drive setup still matters to you i want to make it work.

[bob80817-dev]

I'm good for now with it being on C drive. It's just that it's only 2TB and I'm down to 500GB, and even though I have the money, I refuse to pay for inflated prices today due to shortages.