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

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 !

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.

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.

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

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

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.

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

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.

Excellent 👍

Hello, @JonesVid,

I located the bug report. I am watching it. I will continue campaigning for a fix on this issue. More to come.

Thanks,
Kevin