Start with importing only a few mediafiles, the ones you need for your project, and not a folder with probably hundreds of mediafiles. Also wait till thumbnails/audio peak files creating is finished, or turn thumbnails and or audio peak file view off. This is not a solution, but just a work around.

Thumbnails creating and audio peak files creation has been always a showstopper in Vegas and expects some patience of the editor. Once generated the next time you start Vegaspro it should be much faster.

To są pliki, których używam w projekcie. Wszystkie zostaną wykorzystane. Po załadowaniu wszystkich miniatur, ładują się one ponownie za każdym razem, gdy przewijam listę multimediów projektu. Dzieje się tak również po zminimalizowaniu Vegasa lub ponownym otwarciu projektu. Tak się nie da pracować.

These are the files I use in the project. All of them will be used. When all the thumbnails load, they reload every time I scroll through the project media list. This also happens when I minimize Vegas or reopen the project. It's impossible to work like this.

You can try to untick option "Close media files when not the active application".
In my case the option was ticked for ages, but when started to edit projects with many 4K files in it I found the option is slowing down things too much when switching from VP to other program and back.

I watched the video and see possibly K-Lite codecs being used for thumbnails?

I don't use any codecs

Sorry to disagree, but your video clearly shows that K-Lite in some form has been installed on your computer. As soon as I saw the thumbnails without images in your Project Media list, they display the K-Lite "3 2 1".

The above image is from your Project Media, the image below is from the K-Lite website.

I'm using Media Player Classic only. I don't have any codecs installed.

Understood, thanks for the additional information.

With your computer build, things should be more responsive for sure. But I've found on my aging computer listed below, that if I click on a different tab instead of the Project Media tab after all the thumbnails have loaded, performance is better, at least for me.

Instead of having the Project Media tab selected, have you tried having the Video FX tab?

Program ewidentnie zakłóca ładowanie miniatur. Po przełączeniu na inne zakładki, Vegas wraca do życia.

That is what I've experienced myself. The thumbnail building is being done because of K-Lite looking for the thumbnail and making it appear.

Even though you only installed the media player, more than that was installed.

What type of drive is your media stored on?

I only have Media Player Classic installed, without the K-Lite codecs. I have NVMe PCIe 4.0 SSD drives.

Those unpopulated thumbnails show that you have more than just the Media player installed.

But I'm writing this because I don't have any codecs installed, especially the K Little Codec Pack. The thumbnail problem has always affected Sony FX3 files on Windows. Version 22 didn't have this problem; the problem appeared in version 23.

Looking at your PC specifications, your PC is more than capable for the task.

As I've wrote above, I go straight to the Video FX tab.

But out of curiosity, do you have Task Manager open when you start Vegas? If so, monitor CPU and Disk accessing. Things for me do not feel as responsive as in VP22. But I work with Panasonic video files which do not cause any issues. Maybe it is a Sony FX3 file that is doing it.

As for moving clips along the timeline, if I move the clip slowly, it keeps up with the mouse. If my movements are big, there is that delay where the clip doesn't keep up with the mouse. Again, I've found VP22 to be more responsive.

I've written about this and so have a few other people. I think it comes down to the new video engine they are working on. It is a "version 1", and for sure, there is room for improvement. I've rendered the same clips in VP22 and VP23, and VP22 renders faster.

I'm already switching to the competition on DaVinci Resolve. I wrote to Vegas support, filed a complaint, and requested a refund. It's been a week and I haven't received a response yet. By the way, their customer service is very poor.

@lukizap Nothing wrong in choosing which software works best for you. Hope you hear from the Magix team soon with your refund.... Happy editing.

I'm already switching to the competition on DaVinci Resolve. I wrote to Vegas support, filed a complaint, and requested a refund. It's been a week and I haven't received a response yet. By the way, their customer service is very poor.

I agree. I've sent numerous tickets regarding another problem and after their first generic response, absolutely nothing. All I get is the automated email.

Support is non existent.

this is some kind of misunderstanding, there is no customer service here, I only regret the last money I spent on the latest version 23, but this is the last money I spend on Vegas! 

Sorry to disagree, but your video clearly shows that K-Lite in some form has been installed on your computer. As soon as I saw the thumbnails without images in your Project Media list, they display the K-Lite "3 2 1".

The above image is from your Project Media, the image below is from the K-Lite website.

@Reyfox MPC-HC icons are identical to those shown.

* lukizap

K-lite pack often adds mph-hc. Vegas non too happy with this codec pack. Have seen similar problems with Resolve and this codec pack. Have also seen reports that uninstalling k-lite does not restore the original 'overwritten ' codecs. Trust you made a full system backup before installing klite otherwise you may be facing reinstalling windows.

Good luck

MPH - hc does not add codecs

How many times do I have to mention that I don't use the k-lite codec pack? I only use MPC - just so you know, you can install it separately.