Some ProRes 422 Video Preview Files lost on closing and re-opening project

[JonesVid]

Kevin Monahan has suggested I post this for investigation by Engineering

I am getting a random loss of rendered video preview files on Premiere 23.5 well.

Hardware : PC Windows 11 (also does it on my back up Windows 10Pro Intel 9900K machine as well)

• Intel 13900K
• 64GB RAM
• System C drive NVMe 2TB
• Media Cache on Export NVMe Drive 2TB
• Project Drive NVMe Drive 1TB
• Media Drive SATA 2TB SSD
• Nvidia 2070 Super GPU

I'm using Quicktime Hybrid method to create a video master in ProRes 422.

Editing Video on timeline mix of H264 and H265 4KUHD.

Majority of footage recently is H265 10bit.

All previews generated in ProRes 422 4K

Pro Res422 Preview files are big as they are used to speed up export considerably by Ticking Use Previews on Export (in General Tab)

Once you are working on the project and everything is fine in Timeline  you can see the rendered files on my NVMe SSD Project disc in Video Previews Folder.

No red bars on Timeline after render and project save.

Then shut down machine come back next day and Premiere is randomly losing them - not all.

This happens on my Intel 9900K machine as well.

This appears to be a database issue? (or other gremlin) which Premiere uses to locate the rendered files as the files are still there in Previews Folder and you can play them. Files are not lost.

To recover the previews you have to re-render yet again even no changes are made to the project/files.

I am meticulous about making sure before a major project I clear Media Cache etc which are located on a separate internal NVMe fast drive (not the System C drive) but I did try the C drive as a test which makes no difference.

The drive is correctly defined in Edit Preferences Media Cache.

Is there a bug in code somewhere that is not locating the Rendered files once done - so get lost on power down and power up.

When you are working with ProRes 422 files having consitent Preview files available that are pre-rendered is a must for Export to save time.

[jampff]

My original post which led me here: https://community.adobe.com/t5/premiere-pro-discussions/no-yellow-in-timeline-rendering-incomplete/m...

I confirm this issue. Details:

Windows 10

Pr 24.6.1

Original media: Prores 422 LT

Previews: also Prores 422 LT

Video previews are stored at default "same as project" location, on local D: drive

1. Choose a clip in the timeline and Replace With After Effects Composition

2. Add Ae goodies etc.

3. Repeat 1 and 2 for other clips as well as I edit

4. Before closing Pr to take a break, Render In To Out ... (because I intend to use Smart Rending workflow, which is apparently a pipe dream at this point)

5. Reopen Pr and discover that there is once again a red line above all the Ae comps in the timeline.

6. Attempt timeline playback, but no dice... it's as if the timeline was never rendered at all.

7. Double check that the render files are still in the same location on disk (check).

8. Double check in Project Settings that Pr is still looking in the same location for preview files (check).

9. See if preview renders play back in VLC correctly (check).

10. Edit some more, and then Render In To Out again... get the green line and smooth playback back... until reopening Pr when the same problem repeats.

Please help! Smart Rendering is basically nonexistent at this point under these circumstances.

[jampff]

Okay, new bizarre behavior:

This time, after closing and opening Pr, I expected the red line again, but instead I got a yellow line. !!! (Same exact timeline and details as above.)

Turns out the reason it's all yellow is because all the Ae comps are now "Media Offline". No biggie... we've all seen this before, and usually if you wait a few seconds, the timeline populates.

But this time, it doesn't. Media offline for all edited clips (Ae comps, dynamically linked) in the timeline so far.

So, in the Project Panel, I right click the first Ae comp and choose "Link Media". I make sure "Relink others automatically" is checked. I locate the same exact Ae project that the comp is already in (it's already selected in Media Browser without me even looking for it). I click OK.

And, then the clip turns green in the timeline. In other words, relinking the Ae comp (and who knows why it got lost in the first place??? it was never moved) also makes Pr find the preview render in its location as well.

However... even though "relink others automatically" is checked, the other Ae comps are still "media offline". Even though all Ae comps are in the same Ae project file, only the one I manually relinked was restored. Red line still above all the other comps. I suppose I must relink them all individually.

So strange. Honestly, not fun.

[jampff]

Last one for today, promise. It just gets weirder.

So, after once again getting all red lines above Ae comps in the Pr timeline that have been "rendered in to out" MULTIPLE times... then, they stopped turning green even after rendering! I tried it twice in a row: Choose Render In To Out, come back later, and the process has completed: the dialog box is gone, and the playhead is at the end of the timeline (because it always plays all the way through after rendering), BUT... only some of the clips have green over them. The rest still have red.

After thinking "how strange!" (except strange is no longer very strange at this point), I tried again: Render In To Out. I came back several minutes later, to see it finished again... and still, some green, some red, after rendering.

At this point, I just shrugged and decided to give up on Smart Rendering. It's not working anyway... so I may as well switch back to I-frame MPEG previews since they presumably won't keep getting lost. We'll see.

But the final weird thing is... when changing preview file type, the confirmation dialog says, "Are you sure? This requires all preview files to be deleted," etc. I clicked OK. And... the old Prores 422 LT preview files were in fact not deleted from disk. I went back to the folder where they're stored on disk... and there they all were, even after switching preview file types back to default MPEG.

At this point it's just always something new. Prores 422 preview files and smart rendering are apparently there merely for the entertainment value of waiting to see what weird thing they're going to do next.

[MyerPj]

You mentioned in the other thread that you had changed the location of the media cache, I wonder if setting it back to default might be a better solution since you are using AE also.

[JonesVid]

When the Support guys did a remote session with me we tried the Media Cache and location of rendered files in different locations but none made any difference.

My Media Cache is on an internal NVMe drive (2TB) and only gets used for other stuff when I make an export or make the final exported ProRes edited Master. Its cleaned regularly.

All the symptoms we are experiencing points to database problems internally but as several people have already pointed out - you cannot get inside Premiere to find out why these rendered files are not located correctly. This is hard coded in.

Just a reminder - the rendered files all have 'future' dates in Video Preview files folder, usually 1 day in the future from the Windows System, although I have had instances of several days in the future. Weird.

This happens on my Windows 10 and Windows 11 editing machines.

I cannot work this out and the support guys could not either. How does Premiere date tag a file 1 day in the future in a Windows File system?.  ...and why ?

This may not have anything to do with the actual problem of lost files (tbd) but I have not seen this happen with any other SW application I use.

I wish Engineering would come out of hiding and get involved in this thread discussion to help get to the bottom of this issue.

[jampff]

@MyerPj thanks! I actually already did that. I have observed that this strange behavior occurs with the cache is in the default location as well as in a custom location.

[MyerPj]

It's good you noted it. It's a frustrating issue because Smart Rendering is such a great workflow.

[JonesVid]

No more progress to report on this that I have heard from Adobe in last few weeks.

I'm still losing ProRes 422 previews on latest Premiere Pro 24.6.1 now.

@Kevin-Monahan  please do you have any insight on what is going on here as Support guys now not answering at all and have gone to ground !.

Last report 'under investigation'.

No info received on any fixes to try that are in latest Beta versions.

I do not want to do this blind. I'd like to see proper Release notes on potential fixes to try out -   like any professional software organisation should produce for each software release.

Any updates appreciated as always.

[Documentary Dude]

Hello,

I seem to be having an issue with Render Previews instantly being lost in all areas where there is text/titles on the timeline, when I close a project and then reopen it.

Here's what's happening.

1) I have have a sequence with coloured clips and some areas of text titles

2) I render the sequence.  Everything is green and rendered. Looks good. 

3) I close the project.  I re-open the project and all the previews are there, 'except' every are that had text titles that I created in Premiere are missing thier render previews.  

The issue happens every time I render. Exactly the same.  No area that has Premiere created text ever has the render preview when I re-open the project.  It needs to be re-rendered everytime.  All other areas seem to be fine.

I'm wondering if there's a setting I need to turn off or adjust on the text?  Or something I'm missing?  Or is it just a bug?

Any help on this would be greatly appreciated, as this is an important project for work.

Specs:

Apple M2 Ultra

192GB RAM

Previews are being saved to 4TB ssd drive with plenty of space

Premiere Pro Version 24.3.6

Thanks in advance!

[Documentary Dude]

Sorry, Premiere Pro version 24.6.3 

[Ann Bens]

Uncheck Restore Open Sequence when Opening Project in the Preference > Timeline.

See how that goes.

[Documentary Dude]

Thank you for the reply.  I unchecked the 'restore open sequence'.  I then deleted all previous renders and attempted to render the first 10 mins again.  It rendered and looked good.  I closed the project and it worked... the first time.  To test it, I closed the project and opened it again.  The second time I opened it, all the renders for the text/titles were missing again.  But then I closed the project again and opened it again.  There were then randomly 'some' of the renders for the text/titles there,  but some still missing.  Almost seems like each time it's going to randomly have either a few or all of the renders messing for the text/titles.  It's so strange.  I've never had this problem in past Premieres.  Do you by chance have any other suggestions or work arounds?

Thank you for taking the time to respond.  It's appreciated

[Kevin-Monahan]

Hey there, @Documentary Dude,

Thanks for the report. I have also experienced this on and off over the past few versions, as have others. A bug has been filed, but the team cannot reliably reproduce the issue in-house. I think they may need more information. Can you help with that? See How do I write a bug report?

I'm most curious about your render preview settings in your sequence settings. Can you share those details while we await a response from the developers?

I hope we can help you with this soon. Sorry for the problem.

Thanks,
Kevin

[Documentary Dude]

Thanks for the reply! Kevin-Monahan

Full specs:

Apple M2 Ultra

192GB RAM

Premiere Pro Version 24.6.3

macOS Sonoma 14.7

Preview file format: Quicktime

Codec: Apple ProRes 4444

2048x1080

Maximum Bit Depth

Maximum Render Quality

Composite in Linear Color (requires GPU acceleration or max render quality)

- Previews are being saved to '4TB ssd' drive with plenty of space (thunderbolt 4)

- Video files are being saved on a 140TB raid drive (thunderbolt 4)

- 2 hr sequence (with colour correction elements on 1/10th of it)

- Interviews are multicam, rest of the footage is not.

- The missing renders of titles/text are happening over all footage where a text/title exists, even areas with just a simple little clip.

- Side note: I also get random previews missing here and there, outside of the text/title issue.  But those are ones that I've gotten use to over the years. They're unpredictable and there's very few of them. Not like the 'text/title' issue which is consistent and in every area that the 'premeire text/titles' exist on the line.

Things I've tried:

- deleting all renders and re-rendering the timeline. Everything will render and look great while the program is open at that point.  The moment I close the project and re-open it, all text/title previews are missing

- unchecking 'Restore Open Sequence'

- deleting all unused cache

[Documentary Dude]

I just wanted to update you on the state of the render previews.  Tonight when I opened the project, the render previews in the title/text areas were actually all there.  I opened and closed the project three times, and each times the previews seemed to be working (although there were other random shots on the sequence that lost their previews, but I'm used to that at this point).

So I'm not sure what to make of it.  It wasn't working but now seems to be.  I haven't done anything different. 

[MyerPj]

Yeah, I was hoping there was something to your discovery. But I tried yesterday and I couldn't duplicate it. 

[JonesVid]

Hi @Kevin-Monahan 

I have to take issue with your response here.

You may recall I had several sessions with a senior support manager using remote sessions on my PPro desktop on this issue  - he saw with his own eyes rendered previews randomly lost on close and re-opened projects. That was on 24.x version.

He told me later they had successfully reproduced this problem in the test bed. ????. I thought we were getting somewhere, but it appears not.

Since then total radio silence from support on this problem.

Regardless of that - the mechanism that Premiere uses to locate previews on re-opening a project is not exactly known to us as this is in the dark depths of code. It does not even promot us to locate the preview (like Project Files lost)

As each preview is created Premiere is creating a Hex string identifier to the file. Now - you would think this hex string is then registered within some form of internal database (as part of the project file) with a timeline locator.

So when you close and re-open the project Premiere knows exactly where to fill the gaps on the timeline with these previouosly created Previews.

Unfortunately if you are using Pro Res 422 previews it hiccups and loses some of them....randomly.

Getting this to fail is not that difficult - support saw that if you have stacked clips / text / or maybe where you have used warp stabiliser on a complex clip or a de-noiser like NEAT - the preview gets lost by Premiere more often.

These types of Previews are valuable are as they save us time on re-loading.

A lost preview is not lost -  its still there in your Previews Folder and can be played by Quicktime quite successfully.

Other cases of small previews like those created by Transition overlays are also prone to being lost in a random way.

I highlighted some crazy workaround I adopted for complex previews that might take a longer time to render (even with a 4080 Super GPU). As long as you don't envisage any changes to that section of timeline I save the preview with a file name and import into the project panel. That way it never gets lost. Yes it is mad but might save time in the long run rather than re-rendering all the time and have your preview folder bloat to over 500GB !!!.

Previous to retirement 'in the mists of time' I was Technically managing development of Real Time Comms products that might serve thousands of users. In that code we had trace & trap mechanisms to run when we were not sure what was happening in the code.

I am staggered why Adobe can't get their act together and look at where the lost preview mechanism is happening.

i.e. :

Is it lost because the code does not index the location of the generated preview in the first place?.

Is it lost because the code does not know how to handle the ProRes Codec Preview on loading?.

If the code cannot locate the preview is an internal 'Error ' generated??. We don't see anything as users other than a red line on the Timeline.

All these questions could easily be answered by running code traces. My Junior programmers did this years and years ago.

I'm getting totally hacked off with the arrogance of Adobe and why such a core function that users might depend on is not addressed.

Is the problem too difficult for Adobe to address now as the guys who wrote that code are no longer around and other devs won't touch it !. I'm not saying that is the case but one does wonder sometimes......

Why even continue with Previews mechanism if it is not reliable.

If you have access to a render farm using Megawatts of power maybe it isn't an issue as you just keep re-rendering and keep happy.

Seems this will never be solved and the only way to get Adobe to wake up is to vote with our feet and go elsewhere.

[JonesVid]

I know this is a pain for you @Kevin-Monahan but we would appreciate it if you could let us know what internal status on this bug says please. 
No ranting from us doesn't mean it has simply gone away. It means we are tired and battered trying to get Adobe engineering to get their act together . 

[ghpix]

I started another (superfluous) thread here with the same issue before a kind user alerted me to this one. I'm losing renders on ProRes 422 files as well. It was working on Pr24 after some initial headaches, but with the Pr25 update, the unlinked render files and their dreaded yellow line have returned.

FWIW, I took an auotsave of the previous .proj file, moved it to my desktop, then opened it in Pr25. I was then prompted to relink those render files. The green progress bar did its thing, the project opened, and the yellow line remained. I was not able to replicate this, even after closing that project w/o saving.

Please, please lean on this. I'm going to have no choice but to move on from Premiere Pro if this isn't fixed by year's end.

[Wedelski]

I've been experiencing this problem for at least 7-8 years. Years.

It's a problem Adobe is either aware of and can do nothing about, or don't care. Every year I think "this is the year they fix it" and they never do. In the latest iteration, I will render, save, close and reopen, and the render files will half load. The othjer half will return to the red render state. I don't get it, why it's happening, why nothing is ever done about it.

But they have our money already so whatever, enjoy those new features. 

Disgruntled in 2025, 
Paul

[JonesVid]

Nearly 2025 - problem still there.

Why Adobe , ????

[JonesVid]

Thought I would share my my latest update on the 'ProRes previews lost topic.'

After throwing my toys out of the pram on this one with support - a senior support guy phoned me last night to confirm what exactly was going on.

He confirmed 100% this is definitely being worked on by Dev/Engineering.

No timescales yet - but agreed it was taking a long time to see a fix. Indeed.

As expected,  a fix will appear in a Beta Release first - hope there is better visibility which one it is, rather than test each release.

Anyway, play the waiting game as no more we can do.

[MyerPj]

Thanks for the update, well done! 🙂