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

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.

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.

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.

My original post which led me here: https://community.adobe.com/t5/premiere-pro-discussions/no-yellow-in-timeline-rendering-incomplete/m-p/14861382#M528978

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 😧 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.

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.

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.

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

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.

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 !

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.