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

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

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.

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 . 

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.

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

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!

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.

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

@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.

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.