Windows 10: Windows 11 Thumbnails doesnt show up Image/Video

Hello, I have an windows 11and yesterday at the morning I tried to use an boost fps utillity and chose "Visual optimization", after that my thumbnails dissapear, I tried to restore it by things I found in internet, like the tips of going to the regedit and fixing HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced "Iconsonly" to the 0, and DisableThumbnailCache, and it wont help, I also tried things in explorer like the disabling/enabling icons showing up, and such a thing as"taskkill /f /im explorer.exe ""cd %userprofile%\AppData\Local ""attrib -h IconCache.db ""del

:)

 

Some images and video won't show thumbnail in windows explorer

Some of my images and videos , wont show an image. Some show thumbnails and others show the image. I have gone into VIEW > Options and unchecked show thumbnails as many sites ask but it doesnt resolve the issue. See the screen shot below

 

Video Thumbnails not showing. Image thumbnails work fine.

Video Thumbnails not showing. Image thumbnails work fine. if i change .mp4 file to .vob the icons show a preview again

 

Windows 10: Thumbnails for videos stopped showing (although images show properly)

Hello,

I just recently noticed that every video, no matter if I download it or create it directly on my pc, doesnt show a thumbnail in the explorer and instead just shows me the standard icon for whatever program I have selected as my standard (yes, changing the standard program doesnt affect die issue). Weirdly enough, I noticed that every video I had created or installed before about 10 days ago still has a thumbnail.
Next step was that I tried to find somebody who reports a similar issue in order to find a solution for myself and I tried out all possible options I could find to solve it. However, when I tried to delete my cache for my explorer, it had the negative effect, that all the video thumbnails that were still showing now stopped showing aswell. I then noticed that the only part of my storage, where video thumbnails are still showing is the part that I have connected to my OneDrive and whenever I move a video there, after a few seconds it loads the thumbnail and when I move it out of there the thumbnail disappears again.
I then opened the Fotos program and compared if the same thumbnails will show up (or not show up) in my explorer and they happen to do so.

The only idea that I have on what might have caused the original problem that only new videos have no thumbnails is that it has to do with the "heif image extensions" that I bought from the microsoft store around the time I first noticed my issue.

I have tried a lot of different things to fix it, including all of the methods named in this video



and a bunch more but I have not yet found somebody who describes their problem as equivalent as mine, which is why I decided to open another post.

I would very much appreciate if there is somebody who can help me and feel free to ask me more questions if you need more information in order to help me to fix it.

Thank you!

Edit: I managed to get back my thumbnails with the K-Lite Codec Pack, but Im still curious if there is another way to fix it that doesnt require a 3rd
program. Apparently it has something to do with the codecs