Leave internal preferences alone, there is not any need to change them anymore (they've added a switch to turn so4 off and on in preferences now, under file i/0, as "enable legacy decoding". You might want to reset your settings (hold ctrl and shift when starting VEGAS) to stock to make sure there aren't any internal setting conflicts going on.

Also, you only want to enable legacy decoding (what disabling so4 is called now) if you absolutely must, as the older decoder is slower, and cannot decode 10 bit and certain other formats.

So, make sure your internal prefs are on stock settings, and make sure that legacy decoding is disabled. See how it works. From there, you can start enabling legacy decoding to see if that helps.

Thank you.

"Enable legacy AVC decoding" seems to make things run smoothly again. (I won't have time to do extensive test/editing for a while.)
I noticed that when it's selected, it automatically turns off "Hardware Decoder".

Now, I'm surprised that such widespread cameras as 5D Mark IV and GH4 are already requiring "legacy" decoder...

These media don't require legacy decoder (they are fairly standard AVC), but if there is a problem with your GPU and Vegas and certain media then you might have to enable it. Yes, it turns off hardware decoding, so you are limiting Vegas's performance by going back to it.

What I would do is what Fr0sty recommends. Reset Vegas completely and clear the cache (hold shift-control on startup) as you've been making changes to the internal settings even you don't remember anymore. Ensure you are on the latest GPU drivers and try again. If it still fails, use legacy decoder for problem footage.

What I would do is what Fr0sty recommends. (...) as you've been making changes to the internal settings ...

The ONLY thing that I changed to internal settings is So4compoundplug  because it was the only way to make Vegas stable.

And yet I did resetted Vegas 18 settings.

What problem can there be between my GPU and Vegas ? Using Geforce 1080 Ti, I think it's rather standard, recent drivers (not necessarily the most recent ones).

One thing I'm worried about that I have the same workflow since like Vegas 16, upgrades bring me almost no improvements but usually breaks things that worked fine previously...
 

Oh good, if you reset it to defaults and are on a recent studio driver it should work (fingers crossed).

Non-studio drivers have had some app-breaking bugs recently according to other user reports. Personally I was quite annoyed at Vegas last spring, having constant crashes with my GTX 1050. Switching to the studio driver and putting file I/O decoding back to auto (which is Intel iGPU in my case) got rid of most of them. It also fixed crashes I had with Resolve.

By the last build of 16 it was stable for me. 17 wasn't so good until the end. 18's been fine. Performance has increased- try a render of the same project in 16 and 18 and 18 should be a good bit faster.

By the last build of 16 it was stable for me. 17 wasn't so good until the end. 18's been fine. Performance has increased- try a render of the same project in 16 and 18 and 18 should be a good bit faster.

My memories are more like every update since Vegas went from Sony to Magix made it feel more and more unstable with random crash. Latest build of 17 is rather good for me though, but it also crashes some times.
Ignite/Hitfilm plug-ins which used to be bundled with Vegas and that I make extensive use of have some unsolved Win10 compatibility bug... (but that's not Magix).

And more and more things that I use are becoming "legacy"/"deprecated" stuff... (no regards to backwards compatilibility)
The only really change in my workflow, now that I remember, is that since 2016 or 2017 I think I output 4K...
And just for this, I'm paying for Vegas Suite almost each year ... Feels a bit like I'm giving charity to the developement of this software inn hope that it's at least maintained and that someday I see a real improvement...
 

Interesting. My workflow is also mostly unchanged and I've been finishing up projects I started with 12 and 15 of late. I'm using mostly older Canon h264 movs and newer Sony 4K XAVC-S. Magix VP 15 was a mess and I had all kinds of issues, especially with renders. It's the only software purchase I actually regretted.

I upgraded hardware and Vegas to be able to do 4K without proxies and last build of 17 and all builds of 18 have been solid for what I do. I don't have many plugins, though. The main one I use is Graide Color Curves and it's stable. PluralEyes compatibility is unchanged. I got NeatVideo recently and it works well.

I reinstalled computer in July and now I get the same troubles again. Above I wrote ""Enable legacy AVC decoding" seems to make things" ... but where is ""Enable legacy AVC decoding" ? I thought it was in Preferences > Deprecated Feature but can't find it.


(I tried turning "Shift+Options > Internal > Enable Legacy (Mainconcept AVC/AAC..." to TRUE, but it didn't solve the issue.)

(I'm still using Vegas Pro 18 at this point.)


Ok, I found "Enable legacy AVC decoding" again (it's under "File I/O", not "Deprecated" tab) and Vegas stopped freezing because of those files. Though they remain "difficult" to read it seems.

Vegas stopped freezing because of those files. Though they remain "difficult" to read it seems.

If you're already rehashing the old thread -it's high time you documented your system environment in your signature - otherwise everyone who wants to help you will have to search through the whole thread again.
It's only in your interest - hardly anyone wants to take that much time.

Thanks, well I don't think that my system environment has any use in it, and when I posted yesterday I thought the problem was solved "enough" and that I was just adding a bit more documentation to the solution...

CPU: Threadripper 2950x, GPU: Nvidia GTX 1080 Ti, Samsung nVME 980pro, Windows 10 Pro, 32GB ram, what else can be useful?

But now I just realised that files from GH4 are making preview more of less crash and Vegas unresponding for like 30 secondes. Files from Canon 5D Mark IV start stuttering then turn black.

I noticed that if I reduce the quantity of render thread (default was 32), things get more stable.

I noticed that if I disable the track effects, and I really don't have a lot there and I do need to be able to use them, and if I keep preview quality very low, file from 5D Mark IV read fine, file from GH4 still crashes.

I thought of starting a new thread (because at some point the problem seemed different) but I just didn't know where to start... My old test project started crashing, and then after I renamed tracks, it was working perfectly so could not reproduce the issue.

It's a "template" and camera setup I more or less used on hundred of videos, since 2016... (with a few evolutions though)

I noticed that the last project I finish 6+ month ago (my pace got slowed down during lockdown and other things), was still in a Vegas Pro 17 file.

At the time I'm writing, with 8 render thread, GPU video processing on, Dynamic Ram to 0, preview in "Draft (auto)" it seem like both file play relatively not too bad right now, but it also feels like if a fly sneezes somewhere in any country, the whole Vegas 18 thing is going to break again...

I'm using the latest Studio driver 472.12 on my laptop (1050ti) and a desktop (1660) and it works fine for me. Using DDU is recommended, especially when reverting to an older version.

Using 472.12 too (1080ti). I did not use DDU when upgrading (and never downgraded since re-installing system), should I give it a try?

CPU: Threadripper 2950x, GPU: Nvidia GTX 1080 Ti, Samsung nVME 980pro, Windows 10 Pro, 32GB ram, what else can be useful?

It would be useful if you wrote your system environment in your profile under "Sigature" - then it wouldn't be hidden somewhere in the text and we wouldn't have to ask again in a next thread - and you wouldn't have to write it again..........
As an example, you can see my signature or those of others.

Will do that...


Oh no ... I just have identified (one of) the cause(s) ... You're going to think I'm crazy but I observed this over years on various computers, when I leave a YouTube video on pause,after a certains time, it starts messing with computer performance, espescially for things the use GPU. I thought it was gone, especially since I turned of some GPU related stuff in browser. But I just observed a few minutes away that it cause the 5D Mark IV file to turn black in Vegas, when I unpaused and re-pause the Youtube video, the problem was gone.

Now, I don't know if this is the only cause for my troubles in Vegas ... time will tell...

(Edit a few minutes later: Well, it is clearly not my only source of troubles... black preview again now...

... or maybe it is ... I just close all open browers (tabs) and video unstuck ...)

But now, I split the event in two (for 5D Mark IV video) ... and now preview is all black and stuck and crashing again (+when I close and open Vegas if load "untitled" instead of my project). (I need something to bang my head on right now.

Edit later: No, definitely not getting any image other than initial still frame from GH4 and 5D Mark IV files... SINCE I split the 5D Mark IV event in 2 (and if I could go on on with this project, I would need to split it in more than 2 parts...

I gave up and converted both problematic files to uncompressed .avi ... It's a very heavy step if I have to this every time...

(I also noticed that the presence of these files in the project tends to slow everything down ... like ... copying an "empty event", totally unrelated takes minutes, if files are removes, everthing turns smooth)

You could post a snippet of this file that is causing problems on Dropbox or something, then other users could check it in their system environment - or even forward it to the development team if they have an opinion.
That way you could at least determine if the problem is in the file or in your system.

PS:
Thanks for filling out your signature - it saves a lot of back-and-forth questioning.

I can't post the precise files I'm working, very big in total + theoretically privacy issues.

I would just re-post the same sample project that is is still available on page 1, which contains samples of each of my cameras. But last time I tried that sample project, it was working just fine.
And back then, it was solved by simply checking "legacy" stuff in File I/O, which apparently is not enough anymore.
Yesterday, in my actual project, I had moments when everything was working just fine and moments when just clicking in Vegas seemed like achievement... the only thing I'm certain is that if I those file are in muted tracks Vegas is more usable, and if those tracks are completely removed from the project it's even better...

(PS: Sample project from months ago: https://4dm1n.net/private/TEMPORARY/20201110-vegas-forum/20201110-Vegas_Pro_18_Preview_test.zip )

What I noticed - even before a test - in your notes in "Notes.txt":

Downgrading NVidia drivers to latest "Studio drivers" (v457.09) instead of latest "Game Ready" branch.

We are currently at v472.12 - have you tried this driver and installed it with Vegas "Help /Search for driver updates"?

That "Notes.txt" file was written months (November 2020 from the timestamp in filename), since then I upgraded drivers multiple times and did a full reinstallation in July. I'm also now using the "creation/studio" drivers (I don't remember the exact name), but in the past I was recommended to always use "Game Ready" as the other branch was too far behind. And yes I'm using 472.12.

I did not use your "*.veg", but only put the naked files into my timeline for the test.
Since a *.mov" is included, I activated Quick Time Plugin in Vegas Pro 18 and 19 under "outdated versions" - but this didn't help.  
Since I also use Vegas Edit 19, I also did the tests there. It looks like the developers have done something with Vegas 19 as far as the stability of the problematic files is concerned, only with Cam 2, the mov file were black pictures.

But how exactly to interpret the test, I simply lack the expertise - maybe one of the specialists here knows more.

Here is my test:
Cam1-Panasonic_Lumix_GH5s
Vegas Pro 18: slight, short jerks, display 50p briefly breaks every few seconds to approx. 48 frames.
Vegas Pro 19: no jerks, display 50p does not break in.

Cam2-Canon_5D_Mark_IV
Vegas Pro 18: mostly black image, image is only rudimentarily displayed
Vegas Edit 19: sometimes black picture, especially when rewinding, 50p display does not break in.

Cam3-Panasonic_Lumix_GH4
Vegas Pro 18: sometimes black picture.
Vegas Edit 19: no jerks, 50p display does not break in

Cam4-Sony_Cyber_Shot_RX100_V
Vegas Pro 18: no jerks, 50p display does not break in
Vegas Edit 19: no jerks, 50p display does not break in

PS:
According to the developer, the "Studio" versions of the Nvidia drivers should be used because they are more stable.
The "Game Ready" drivers are only updated so often for the many games that are constantly coming onto the market.

@TTTT
Can you do anything with my results?
Feedback would be appreciated

Well I read them, and it's interesting for me that someone else notices similar problems...
But I'm not sure what I'm supposed to "do" with them.

(Also I finished this short current project (shot in 2019) with uncompressed .avi for 2 cameras, and another longer project at the same time, so now I start archiving phase (I archive project files + uncompressed .avi render in .rar archives so it takes some time) ... but for next projects I will try upgrading to Vegas Pro 19 (I bought licence the day it came out but didn't want to change while projects were under works) ... But I still have video files as old as 2017 to edit so, I'll see how things turn out.)