Some effects aren't working.

Hello,
Sorry for my English; I am using Google Translate.
I have been using Kdenlive for quite some time, across multiple versions and on various computers.
I am currently using version 26.08.1 on a Windows 11 HP ZBook.
Overall, I think the editor is very well designed—kudos to the developers.
However, there are a few features I would like to use but can’t seem to get working; I’m not sure what I’m doing wrong.
For example:
Transform → Composing is well-documented but doesn’t work.
Or Misc → Face Detect / Face Blur: there is no documentation, and the features don’t work.
I can’t find any information on this anywhere. Can anyone help me out?
Best regards,
Robert Leininger

I can’t help if you don’t tell me what you expected to happen and what happened as a result.

Oh, sorry. With the “Transfer Blend Mode,” I expect that setting a mode will cause the clip to be composited with the image underneath—just as described in the documentation. But no matter what I set, nothing changes; the clip simply sits on top.
With “Misc,” “Face Detect,” or “Blur,” I expect a face to be highlighted or blurred. But no matter which slider I adjust, nothing happens.

sorry, “Transfer Blend mode” means transfer Compositing.

Or is something wrong here?

I don’t see anything wrong with that. Object Segmentation using the SAM2 AI models meta (facebook) created is an optional plugin and the devs are considering removing/replacing that in the future because it’s a pain for the user to setup (they said that in yesterday’s stream). So that has nothing to do with the issue at hand.

As for your effect issue, I’m still a bit confused on what’s going on, but I’ll try to help. Imagine track based editors as like stacks of paper on top of each other, here is my attempt at importing a screenshot from a TV show (south park) and the leaning tower of pisa together (including with blending mode)

The two things you’re compositing against have to be vertically above or below each other. I hope this helps.

These effects show up in Misc because for some reason 26.08.1 shows all effects available from the frei0r and avfilter libraries although they do not work. Please ignore them.

Thanks for the effort, but that’s exactly what isn’t working for me; the clips just sit on top of each other regardless of the settings.
I’ll try to explain it in more detail and get back to you later. I have to head off now.

I’ve now created an MP4 file that shows the error.
But how can I include it here?

You can use imgur: https://imgur.com/upload

https://imgur.com/a/9ugQFPg

Thanks for the tip!
As I mentioned, it doesn’t work on any of my 3 computers—HP machines running Win 10 and Win 11, with i5 and i7 processors—and this has been the case since at least Kdenlive version 24…
Thanks for your help.