Upgrading catalog with 13-3 loses previews

[Biscut]

I needed to upgrade the catalog with the new Lightroom Classic update about 10 days ago (now 13.3). However, it seems that the previews were not included. In the same folder, I see the old preview catalog (500 GB) and a new preview catalog (4.5 GB). I'm not sure why the previews were not incorporated into the new catalog.

I've done several hours of work in the past week (before I noticed what happened), so I don't want to lose anything by rolling back and upgrading again. Is there a way to absorb the old previews into the new catalog? Or any other ideas besides creating 500 GB of previews all over again from scratch? What's the best way forward?

[Ian Lyons]

As of 13.3, Library preview generation has a new architecture. The previous previews are not compatible, but will upgrade on-demand or by rebuilding the entire preview database from scratch.

[Biscut]

All right, thank you. Somehow I missed that as I updated. Is there a way I can update them, or nothing I can do now? How do I do upgrade on-demand?

[Ian Lyons]

You can trash the existing Previews.lrdata and rebuild everything using the 'Build Standard-sized Previews' in Library > Library menu. This could take many hours. As such, it's probably best done overnight.

On demand occurs when you view the images in Library Grid or Loupe view. In this case, you'd prioritise the recent images or those that you're working on.

FWIW, I went for the trashing the lrdata folder and rebuilt everything (140,000 plus images). It took 5-6 hours on my M1 Ultra.

[Biscut]

Thank you again so much. One further question, please; I'm not sure I follow.

My old previews file (500 GB): is it worthless now? Or is there a way to have LR process it to have the same previews I used to have?

If I can't use that old previews file, then I would need to select which previews I want to have at this time, correct? My catalog is some 270,000 images and I don't need previews (I usually use 1:1 previews) for all of them.

The meaning of on-demand is clarified for me, thank you. That's quite slow and impractical at the moment due to something up with my computer I haven't figured out. I'd need to set the previews to be built overnight as you mention.

But if I have a few previews (from those made on-demand in the past 10 days of work in the current (new) previews file), why trash the current (new) previews file and start over instead of just adding more previews to it?

[JohanElzenga]

My catalog is some 270,000 images and I don't need previews (I usually use 1:1 previews) for all of them.

By @Biscut

That statement does not make sense. When you look at an image, in the grid or in loupe view, you are looking at a preview. These are the standard previews, and so you need them for each image that you watch. You do not need 1:1 previews for all of them! A 1:1 preview is only needed and used if you zoom in to 1:1 display, to check sharpness for example. A 1:1 preview does not replace the standard previews, it is extra. That is why Lightroom Classic has the option to discard 1:1 previews after some time (how many times would you check the sharpness of an old image?), but no option to discard standard previews.

Lightroom generates previews if and when it needs them. You can't change that behavior, except that you can render previews for selected images so they will already be there if and when Lightroom needs them.

[Biscut]

Thank you for the clarity. For my part, I should have written, "My catalog is some 270,000 images and I don't need 1:1 previews for all of them." I only need (personally prefer) 1:1 previews for those I am going to be processing. I'm quite familiar with using Lighroom, but what I would really like to know is if my old previews catalog is useless now or if I can save some time somehow by incorporating the old file or processing it to be compatible with the new LR catalog. It was not clear at all to me that all previews would be invalidated with this latest LR update, and that every single photo I look at would need a newly-generated preview. I'd just like to know the best practice for moving forward here.

[Ian Lyons]

Your previews from earlier versions are useless in 13.3.x

As you scroll through or click on images the old preview will be updated to the new format.

[Victoria Bampton LR Queen]

@Ian Lyons Are you seeing something I'm not? I just upgraded a catalog to 13.3 and it quite happily transferred the previews. Then I deleted the previews and replaced them with a copy of the 13.2 previews and it still worked quite happily. I am seeing a few reports of previews not getting upgraded along with the catalog, but it doesn't seem to be the norm. 

[Ian Lyons]

@Victoria Bampton LR Queen 

The OP wrote below in the original post

" In the same folder, I see the old preview catalog (500 GB) and a new preview catalog (4.5 GB). I'm not sure why the previews were not incorporated into the new catalog."

Above is clear indication that something went wrong during the upgrade, although I've no idea what. If the upgraded catalog is indeed using the new previews.lrdata, then OP has no option but to rebuild the previews on demand or in bulk.

Fwiw, the only time I've seen a duplicate previews.lrdata folder is when the upgrade process went wrong.  Also worth noting that the structure of the preview files for each original is different. The preview structure in 13.2 and earlier was a pyramid of X files of different sizes. In 13.3 the preview structure for the original file is X separate files of different sizes. I've attached a screenshot that might make more sense than my description.

Note that I also tried your suggestion of taking the original previews.lrdata and renaming it to include -v13-3. However, when I launched LrC 13.3 a new previews-lrdata-v13-3 was created and the grid cells were all grey. 

[Victoria Bampton LR Queen]

Interesting. Definitely something buggy there. I've seen a duplicate previews.lrdata when the upgrade hasn't been able to copy over the old previews, so it's gone ahead and created a new one, as in this case. But every time I've tested, deleting the "new" previews and renaming the old one has worked. The old preview structure gets replaced with the new one on the fly when new previews are built so that in itself isn't an issue. Are you in the Dark Room tonight? It's on my list to ask Rick.

[Ian Lyons]

I believe it may be related to the size of the lrdata folder / number of photos in catalog, but have no proof. My main catalog has 140k of files and previews.lrdata is 235GB, but it upgraded without issue.

Yes, I hope to get along to Dark Room

[Victoria Bampton LR Queen]

That's my suspicion too. We've had another by email today, 308k photos, 206GB previews, the same thing happened. 

Great, see you there. 

[Victoria Bampton LR Queen · Accepted solution]

Although there's a new preview architecture, the old previews should have been carried over. You may be able to force it by quitting LR, copying the name of the 4.5GB previews, renaming it to something else, then renaming the 500GB one to the 13-3 name you just copied.

If there was an issue with the old previews, this may fail to work, but if there wasn't, you may have all your old previews back. They'll still get replaced in time, so if you've got the originals online, building the previews from scratch may still be a better bet, but this is potentially an option if the originals aren't available. 

[Biscut]

Renaming the catalog to the old one seems to have worked. Though my computer has been so slow lately as to make it difficult to determine if LR is loading a 1:1 preview or creating a new one on demand.

Thank you all for your help on this issue!

[Michael Kowalczyk]

Hi I experience the same problem after catalog update and now my preview file is not building. Its stuck at 75 from 500K images. Any suggestion how to get it rolling? Thank you!

[alanjr_uk]

Just wanted to add I've been hit by this too - only 20k photos in my library thought so pretty small compared to most of you!

Upgraded catalogue to 13.3 and noticed all previews missing. I was travelling at the time so didn't have access to the originals to recreate the previews. Thankfully downgrading to 13.2 resolved the issue but am holding off upgrading to 13.4 or later until we know the bug has been fixed. Do we know if Adobe have acknowledged the issue?