Thanks for your quick reply! All this looks like is a typical timeline with no nesting and no obscure video formats, and anywhere you put the CTI it will not show video on the preview screen (and yes, I just realized and edited up there that I made sure the video editor has the program/preview monitor active; not the trimmer). If prerender is attempted, it's all green but a big black box in upper left; if not, then all preview is black.

Okay, just wanted to help.

As the saying goes, "a picture is worth a thousand words", that's why a screenshot was requested.

To "me", and I could be wrong, your computer is underpowered to use Vegas. Update your graphics driver for your Intel Celeron processor first. Accordingly, these are the min specs for VP17:

Microsoft Windows 10 (64-bit)

4-core 2.5 GHz processor

for 4K 8-core 3.0 GHz processor

8 GB RAM

Graphics: Dedicated, at least 512 MB VRAM

internal sound card

1.5 GB for program installation

Internet connection: Required for registering and validating the program

This program requires one-time registration

Thanks, DMT3, for wanting to help. I understand that's why you replied. I appreciate it!

Thanks for your reply, Reyfox. 1. My computer isn't underpowered for Vegas, because if it were then I wouldn't have gotten to the state of being what I dubbed as "things were going along fine." It would play back choppily but then prerendering would fix that as expected. Something had to have broken the render engine but just a regular uninstallation and reinstallation of the app isn't enough, and maybe I will have to uninstall the app again but this time also delete all the Windows registry entries that refer to Vegas, or even reinstall Windows from scratch.

2. I could go to the trouble of making and sending a screen shot (which was not actually required; just suggested). But what would it supposedly show other than what I've already described in the main post and follow-up replies?

3. What do you mean by if it were up to "me" in quotes? Like... not actually you? What if it were up to... ACTUALLY you (besides upgrading the computer, since mine was running just fine up until just now)?

My opinion, and it really isn't, but what Vegas lists, is that your computer is under powered to use Vegas Pro. It does not meet the minimum specs that I posted for VP17. That doesn't mean it won't "work", but many features will not be available due to your hardware limitations.

There can be many reasons why you are experiencing problems. Open Task Manager, load your project, and see how much RAM is being used. You might be exceeding your RAM and the computer is using virtual RAM, writing slowly to the hard disk.

What do you mean "pre-render"? How do you do this?

If someone is willing to help you and asks for additional information, it is so that they can possibly help you. A screenshot is something that isn't hard to do and to add to your post.

When I have problems with software that used to work but doesn't now, I look to see if Windows updated anything on my computer. Then I use Revo Uninstaller Pro to do a "nuclear" option of removing the software including all the folders and registry entries. There is a free version of it HERE.

And finally, using another free piece of software, MediaInfo, and post what is in View>Tree.

FYI, for the next time, "If VEGAS Pro is behaving strangely you can try resetting it to the default settings." (Please note that it is NOT the same as reinstalling, which "pretty much keeps the old settings".)

Again, @Reyfox, it was working fine, if only a little choppy before prerendering. Being a bit underpowered doesn't take something from running fine to suddenly majorly broken, or "broken" as I thought. I did have to reinstall it to fix the weird blank-green rendering problem, and then untick the "Mute all video" in the Options menu, but those are both fixed now. It had nothing to do with my RAM. But being choppy before prerendering the timeline might have something to do with that, though.

Being maybe underpowered also doesn't block me from any of the features that I have tried to use so far. Maybe something like multi-camera roll wouldn't work very well but you're not stopped from trying something like that just because the computer is supposedly underpowered.

I didn't mean anything *BY* "pre-render," because I never said that. However, the closest thing to that that I said was "prerender(ing)." And that is what you use to play the timeline with your edits when you're doing this on a computer that is a bit underpowered. The NLE will still work on these machines but prerendering the timeline helps them along. And you do it from the Tools menu or by pressing shift-M. A high-powered computer like the one I'm about to build probably wouldn't normally need that.

Yes, I know that when someone asks for additional information, what it's for. Making and attaching a screen shot wouldn't have shown something beyond what I described, unless we had gone through and shot at least one of the menus.

Thanks for your recommendation of Revo Uninstaller and MediaInfo! I will try both of those.

FYI, for the next time, "If VEGAS Pro is behaving strangely you can try resetting it to the default settings." (Please note that it is NOT the same as reinstalling, which "pretty much keeps the old settings".)

Thanks, @vkmast. I know that reinstalling and resetting aren't the same thing. I had to reinstall it because it went into this weird non-rendering with the green-and-black blank picture. I had to dig around in the menus--or learn how to RESET it--because I had also mysteriously gotten "Mute all video" ticked after that, which looked to also be a rendering problem but turned out not to be. However, RESETTING is why I wish reinstalling would automatically--or at least give us the option to--CLEAR the entire Windows registry (or the Mac equivalent, if there even is Vegas for the Mac) from that installation so that you wouldn't have to worry about any setting left over that's still getting in your way!

But yeah, now that I know about this reset option, it may also help when something else comes up! So thank you!
Also, I bet that what you said about how reinstalling "pretty much keeps the old settings" is true even WITHOUT the quotation marks (it's probably actual, not just figurative--no quotation marks needed). ;-)

I used the quotation marks with the "pretty much..." thing because it was in fact a direct quote from a 2014 comment by a seasoned user.

@MikeA-Christensen Hi, without being provocative you rejected all help offers, when you ask for help you should comply with the requests or what's the point in posting in the first place, it's how conversations & therefore solutions are found, 🤷‍♂️, this whole post has been you turning down all suggestions & the "Solution" you labelled was to reinstall, that's not a solution, it's a complete restart, you didn't recognise the problem (your underpowered PC) & no doubt in the near future you will be reinstalling again, If you'd accepted the help offers maybe some compromise could have been found & a learning of the limitations of your PC + Vegas,

' Being a bit underpowered doesn't take something from running fine to suddenly majorly broken, or "broken" ' - wrong, your pc is quite seriously underpowered & the reason why you had to reinstall Vegas,

Prerendering - 'A high-powered computer like the one I'm about to build probably wouldn't normally need that.' - I prerender very often , esp on 4k

@vkmast I sort of understand the quotation marks comments, sometimes that can be misunderstand as sarcasm or patronising, Google - 'the general rule is that double quotes "_" are used to denote direct speech. Single quotes '_' are used to enclose a quote '

There is an option for a "mute all video" button to appear in the timeline toolbar. You can check for that in the config dialog that comes up for "Options -> Customize Toolbar". The icon for that button is cryptic.

I used the quotation marks with the "pretty much..." thing because it was in fact a direct quote from a 2014 comment by a seasoned user.

Oh, I see, @vkmast, thanks, heheh.

No, I was not "rejecting" help offers, @Former user. For examples:

1. Just because someone asks what sending a screen shot would supposedly help with that the description supposedly might not have isn't the same thing as telling the person that you "don't want their help."

2. Just because someone says a computer is "too underpowered" and that's supposedly "why the software broke" or "why video rendering quit working," and the receiver of that reply counters with the fact that it's not because being underpowerd doesn't suddenly cause things that were working fine to stop working all at once, and that upgrading this one or buying another one "should fix the problem" isn't the same thing as telling the person that you "don't want their help."

Besides that, I proved that wasn't the problem because of what I've already explained were the problems instead. Even higher-powered computers corrupt their software installations from time to time, and the whole black-screen thing after the green wasn't even about that. If you had read my solution reply all the way through before replying, you would have known that. I said that I accidentally ticked a weird option in one of the menus that did that; that problem had NOTHING to do with computing power. So what I said in my solution reply actually WERE the two solutions. So no, I was NOT rejecting others' help; it just turned out that what I did WAS what fixed it. And it's still working now.

I asked @vkmast about the quotation marks because at first he did not make it obvious that he was using them to indicate an actually quoted phrase instead of just the quotation of an idea that some people have had that he didn't believe himself or is just generally figurative instead of actual (the "sarcastic quotation"). He cleared that up later, though.

Thanks, @bvideo, I already found that and unticked it. I don't know how it got selected in the first place, but that's how I fixed one of those two problems.

TO ALL NEW VIEWERS OF THIS POST: THE SOLUTIONS WERE ALREDY FOUND AND USED; NO NEED FOR NEW SUGGESTION REPLIES, BUT THANKS FOR READING AND WANTING TO HELP. HAVE A NICE MONTH! 🙂

For the button in the timeline toolbar, you don't "untick" it to make it go away. I saw earlier in the thread that you unticked the option menu item. That's a different spot in the GUI. There's a slight chance the button in the toolbar could still be lurking there to be clicked inadvertently. Very sorry for the unsolicited reply 😄.

Thanks, @bvideo, I already found that and unticked it. I don't know how it got selected in the first place, but that's how I fixed one of those two problems.