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.

[JonesVid]

Hi @Kevin-Monahan 

I have just tried to see if I can get any information at all from Adobe Product Support on this via Chat.I did request Video Queue but this did not seem to help much.

I have not used this facility for many many months and I probably won't be ever again.

They remotely disconnected me twice after I entered my support question. On the third attempt I was told the fix was to just delete all the Preview Files and re-render again.

Don't know how this Support facility is still allowed to run. It a disgrace.

I thought it was a longshot to see if they could give any news on the bug given that a Bug Report had been filed internally (as per your note)

Apparently not.

[Kevin-Monahan]

Sorry for that negative experience, @JonesVid - I will escalate your issue. Let me know via PM if you do not hear back from them in the next 3 business days.

Thanks,
Kevin

[JonesVid]

Hi @Kevin-Monahan 

Thanks for acknowledging the post and stepping in.

The level and quality of information users get back from this support service is like a lottery.

As mentioned, I assumed they may have some visibility of this 'internal' lost previews bug report they could access to ascertain status. That's all.
Eg: Under investigation, pending or whatever ...

My assumption was obviously misguided.

As this has been raised internally we have no case reference to quote when speaking to support and assume this will not be in the public domain anyway.

I do look forward to receiving an update.

[Kevin-Monahan]

Hey @JonesVid,

This issue is being worked on. Can you verify whether your lost render files are mainly related to captions? Let me know. They are in my case.

Thanks,
Kevin

[JonesVid]

Hi @Kevin-Monahan 

Thanks for the feedback

From my experience, it seems the actual previews that get lost can be totally random, but I have found a possible correlation to transition effects that get overlayed on top of the 'cut'

These are generated by an add on Adobe Extension Transitions package that places necessary effects on top of the main Video tracks.

Its not the package itself as it relies on Previews being generated that are of course stored in the Video Previews Project Folder.{Also no problems on earlier Premiere Pro versions].

After successfully generating the transition (working fine with smooth timeline playback on ProRes422) - and able to see that corresponding transition preview files in Preview Folder, if you close the project then re-open it, some of them are lost on re-opening project, not always the same ones.

In addition, if I have a complex clip with animation, Lumetri effect (and some nested clips) which has its own ProRes422 preview file - that also may get lost in a similar way.

I'm working more or less exclusively with 4K UHD 50fps now, so have set up a preset Sequence for that plus Quicktime ProRes 422 Previews with same 4K UHD dimensions.

The support team accepted there was an issue on loss of previews with their tests, but did not say under what conditions they replicated the problem.

I'll do some more tests with Captions to see if I have missed that one and post results here

[JonesVid]

Hi @Kevin-Monahan 

When you say 'Captions' - are these specifically from Transcribed speech?

As I don't use them, just wanted to check !.

I am using pop up text / titling but no correlation with lost Previews found  there specifically.

However ...

One additional scenario for losing Previess that I need to add -

Previews can also lost when some more complex tasks are applied to a clip which requires a new Preview.

EG: I have Neat De-Noise 'plug in' which appears in the Premiere Pro Effects Panel - drag on video clip on timeline which opens new Neat Video UI on which you can select De-Noise actions.

Needless to say when you are then generating a new ProRes 422 preview from that clip it can be very large.

The Video Preview can be seen in the Previews Folder - and you can play it in Quicktime Player.

On reloading the project (say the next day) you get red bar above that clip ..... so it is lost according to Premiere Pro (but it is still there in Previews Folder!.

Have to re-render all over again. aagghh

What makes matters worse is also the additonal  'Use Previews on Export BUG' which then means it re-renders on real time export in same ProRes 422 codec yet again (even though you have a green timeline) and you have to wait ages - even with a fast GPU .

I think I described this on my earlier community post.

To overcome all this,  I have to do a long work around and import the Preview ProRes422 Preview Clip  as an 'External Clip' in the Project Menu.

I then replace the original clip on Timeline with that 'Quasi External Clip'  by dragging it from the project window. This is where I start gritting my teeth ...

Premiere won't lost that preview now as it treats it as an Imported Clip. But what a hassle?

For goodness sake Adobe please get these things resolved, we have waited long enough

Some feedback would be useful too.

Thanks.

[MyerPj]

I'm pretty sure nobody envisioned loading in the preview file to timeline. ugh...

It's a great feature, if they can fix these inconsistencies, to me it's the best workflow going.

[JonesVid]

Yes indeed, importing a preview as an Imported Clip is a bit bonkers but seems the only way to stop losing Previews that have taken a long time to render and saved as a ProRes Preview as my example above explains.

I also use Topaz Video Ai and I think once they release the Plug In for that in Premiere Pro I will encounter the same problem - where a timeline clip has been processed and stored as a Preview (just a hunch).

That means you will have to generate a separate Pro Res file and import as a Clip again (based on my current experience).

This will be even more bonkers !

[JonesVid]

Well I've just spent a wasted hour on support chat to try to see if the case I raised on this (as a bug report) had any updates.

Support assigned a case back in April for my Bug Report and confirmed loss of Previews issues had been replicated.

Support have closed the case now as they have 'done their bit' so trying to follow this up is impossible.

Is this good quality customer support ?

[Avisekh Mukherjee]

I have exactly same problem for many months now. Contacted adobe support and they deleted the preview files created them. Saved in another project. Nothing happened. New project same issue. I gave up and every time I start I would render the pending one that I already rendered last time. Premier is not Resolve. So most of my files wouldn't play smoothly in right quality; which I feel needed for the right color grading. Hence a rendering of preview is important. But needing to render the same file again and again without any change evety time I open premier is just waste of time. Definitely a bug in premier. But not sure anyone in adove is listening any doing anything about it. They are all busy creating AI. Forget about basics broken!

[JonesVid]

I suggest you also post a bug report on this with details if which codec/formats you are using and a few details of your editing platform.

The more bug reports on this Adobe support receive the better.

i raised a case earlier this year and now progressing this regularly.

[Kevin-Monahan]

Hello @Avisekh Mukherjee,

Thanks for your bug report. The team will need more information: How do I write a bug report?

I suggest you also post a bug report on this with details if which codec/formats you are using and a few details of your editing platform.

By @JonesVid

It would be OK to leave the details I just requested here in this thread. No need to file a new post. Just make sure to upvote. I did! Less rendering = more free time for real life.

Cheers,
Kevin

[WrestlerEditor3]

Another +1 bump for this issue. This has been an on-again off-again issue with Premiere for the decade+ I've been using it. I remember in the good old days of FCP7, this was such a smooth process. You'd render, you'd have your render files, and they would be connected. 

I'm on a iMac Retina 5k 2019, Intel Core i9, Vega 48GB Ram. Premiere 24.3.0 (Build 59) MacOS Venture 13.5.1

I've rendered many BRAW clips with a third-party denoiser to ProRes422, going to our firm's central server.

I just rebooted my machine.

I've restarted PP24, now faced with half a timeline of red renders that I left going overnight. 

I'll have to render as much as I can over my lunch break to catch up to where I was 3 hours ago. 

Please help, Premiere has been losing my render files since I joined Adobe in 2011.

[MyerPj]

That number at the top left of the post (in a browser) needs to go up. Keep upvoting this thread. I believe it's best when one thread goes up in number, then to have multiple threads. But certainly do both if you think that's best. In that case, put a link to your bug report into this thread also, so people can upvote it too.

[JonesVid]

Thank you MyerPj for this important reminder. The more votes on this issue the better.

If anyone has specific conditions where particular video previews disappear on project closure and re-opening (E.G. type of clip or attributes) then please describe in a post here. Being able to replicate a bug easily is more than half the battle in helping resolve it.

[Lewiscat]

Hi,

I previously entered this in the discussion thread.  MyerPj kindly pointed me here as my case may be related.  I use a Mac M2 Max.  The red line indicator appears above one of my clips when I reopen Premiere Pro to work on my project.  ProRes previews were made and no changes were done to this clip since my previous session and the line was green.  My render file still exists in the same storage folder as before.  Puzzled as to why I have to re-render the thing again.  I upvoted this. Thank you!

Mac M2 Max

PPro 24 - latest build as of today

[JonesVid]

Thanks Lewiscat for upvote. I'm continuing to follow this up with the Support Team. They have acknowledged there is a bug and are investigating it.

If i receive any news on this i will update here.

Seems it is a bug across windows and Mac platforms.

I'm also following with them ( at the same time) the 'use previews' bug not working on media export.

So even if you have all Pro Res renders done in a live project on export it renders the whole timeline again which takes a long time. It does on my PC even with a new Nvidia 4080 Super GPU !!.
I checked the Beta build 30 as Support team thought it was fixed in that, but sadly it isn't yet. Link to 'Use Previews' discussion thread above in this thread.

So working in ProRes 422 is somewhat of a challenge.... 

If anyone has these issues please keep upvoting. 

[TTentertainment23]

Commenting on this to stay in the loop. 

Same annoying bug here; Premiere loses previews, sometimes even moments after re-rendering my entire sequence. 

Footage is:

H264 4KUHD 422 10-bit

Sequence Settings on Preview Files:

QuickTime

Apple ProRes 422

Using Premiere Pro 24.5

macOS Sanoma 14.5

3,6 GHz 10-Core Intel Core i9

AMD Radeon Pro 5700 XT 16 GB

32 GB 2667 MHz DDR4

Will try to switch preview files to ProRes 422 LT to see if that fixes anything. 

Cheers @JonesVid for putting in the work with Adobe to try and het this bug fixed. 

[JonesVid]

Adobe Support continue to follow this up me. They have reproduced the disappearing video previews which is still under investigation by Engineering apparently. 
No timescale yet for a fix - i hope support will let us know when there is a beta fix build to test.

Use Previews on Export

I have been advised to always use 'Match Sequence settings ' as codec on media export.

I has always manually selected this to match my preview settings - Pro Res 422 but that didn't work and the entire work area was re-rendered in export.

Match Sequence settings is a workaround and uses your available Rendered previews to dramatically speed up export. Used 24.5.0 to test.

I will post this info on the 'Use Previews bug thread' as well.

If I have any more useful info on lost previews I will post here.

By the way, I tried ProRes422 LT but made no difference  for me.

[Kevin-Monahan]

Hi @JonesVid,

Have you seen any improvements in version 24.6 or the new 25.0 Beta? Let the developers know.

Thanks,
Kevin

[JonesVid]

Hi Kevin

Away sampling the delights of Normandy at present so will update the thread next week on my return to the UK. Thanks for flagging it !

[JonesVid]

Hi @Kevin-Monahan .

So having had only time to do a quick test on 24.6, so far the results have been positive.

However, it is working blind really because I have had no feedback from support to say if they have found some potential anomalies on why Rendered previews have been lost before - or if they think they have fixed the problem.

I used the test project I used with the Support team when they did a remote session. On the last session they saw for themselves previously rendered clips with Green bars go Red when the project was closed and re-opened again. Sometimes this took a few attempts but it illustrated that internally within Premiere Pro file index/locations were lost.

I have rendered the project again using 24.6 and saved then re-opened/closed the project several times, so far the rendered clips are retained.

I now need some specific feedback to confirm if Engineering/Support have found the source of the problems.

As of yet I have not tried the latest Beta release. As you know these change almost on a daily basis.

So conclusion is - looking good, BUT.... we need some confirmation if any anomalies were found in the way Premiere Pro had been previously tracking & indexing rendered preview files and if support believe the fix actually is in 24.6 release.

As I have stated before, this is crucial to making Smart Rendering a usable and solid workflow for the future, otherwise you spend a large amount of wasted time constantly re-rendering files.

I'll do more tests on this and report what I find here.

If any users in this thread previously experiencing lost Preview files could also do their tests and report the more the better!.

Observation: On Premiere Pro Software releases, the content of release notes is fairly vague and tends to focus on new cosmetic stuff. Very rarely are specific bug fixes detailed at all.

A fix for the issue above is core functionality in the product, not a 'nice to have'.

Thanks for keeping an eye on this one !. Appreciated.

[Kevin-Monahan]

Hello @JonesVid,

The bug remains under review and has not been marked as fixed yet. I apologize that the team has not given you an update. Work on the bug or related issues has probably been done, though, so giving your feedback here is valuable for the community. My hope is that it is fixed. Thanks for the post!

Cheers,
Kevin

[JonesVid]

Update as of 3rd Sept.

Just loaded and tried the latest Beta V25.0.0 Build 44

Lost one preview on project close and project re-open.

Uh - Oh

Still no feedback on this investigation from an engneering point of view.

[jampff]

Agreed, this entire bug makes smart rendering completely moot. Sad, because smart rendering improvements were a huge selling point a year or so ago. I remember being really pleased with it. Now it's like smart rendering never existed. Giant steps backward.