P: Export large Sequences via simple custom export plugin crashes Lightroom 11.4

[Gunther Wegner]

This issue was reported to me by multiple LRTimelapse users that use my LRTExport Lightroom Plugin to export their timelapses.

Symptom: Exporting sequences of multiple thousand images via a custom export plugin consistantly makes Lightroom Classic 11.4 (and later prereleases) crash. This happens on Windows and Mac machines.

There is no problem, with shorter sequences of several hundreds of images, as it appears.

I could reproduce the reports from my users on my machine (Windows 10), latest NVidia drivers, etc.

To exclude the chance of any programming errors in my rather complex LRTExport plugin, I coded a very simple, basic custom export plugin. This simple plugin, also crashes when used to export several thousand images, you can use it to reproduce the issue:

https://www.dropbox.com/s/4om4748izdlaw1y/Gunther_Wegner_SimpleExport.lrplugin.zip?dl=1

The more images I export, the faster and more often the crash happens. With 4000 images for example, often after 10 images Lightroom closes. In some cases it sends a crash report (which I submitted under my info(at)LRTimelapse email address) in some cases it just closes.

Another scenario that I observed a couple of times is that the plugin stops logging and updating the progressbar but the export actually continues in background (filling up the export folder). Then obviously you also can't stop the export via the X button.

I can reproduce these issues in 100% of all cases when exporting several thousand images.

I went back to Lightroom Classic 11.3.1, where everything works fine in the same scenario.

I already spent two days in analyzing this issue and I'm willing to help to provide more information, if I can. It is very important for the timelapse community that this issue gets resolved asap!

Thank you in advance,

Gunther Wegner

LRTimelapse.com

[ulrichf32819305]

Same problem here. Since 11.4 with and without GPU-acceleration LR also crashes with it's own export "E-Mail, to disk without any notice. In one test after 681 exported jpgs (two of them not readable - crash probably during writing process), next one after 361 with the same pictures. The same with different pictures

So no problem with the LRT-export plugin, not a broken file or similar ...

[Matjoezz]

Chiming in here as a member of the global timelapse community. LRTimelapse is incredibly important software and I hope the Adobe engineers work out this bug ASAP.
Thanks,
Matthew

[Luis JG]

Hello Gunther and everyone.
I have the same problem, it's true. Yesterday I was with a sequence of exactly 1,000 photographs and I have the same problem as Gunther says.
Before there were no problems with Lightroom.

Thanks for the collaboration.

[sophieh47611451]

I have the exact same problem. Got a bunch sequences with over 10000 photos to be exported in TIFF. This is a critical bug and absolute deal-breaker and needs to be fixed ASAP. I downgraded currently to version 11.1 since this is also a version that reliably renders on all 32/64 cores.

[Timestorm Films]

I have the exact same problem. Got a bunch sequences with over 10000 photos to be exported in TIFF. This is a critical bug and absolute deal-breaker and needs to be fixed ASAP. I downgraded currently to version 11.1 since this is also a version that reliably renders on all 32/64 cores.

[John R Ellis]

I've been doing tests with your sample plugin.  A couple of necessary changes:

- Rename "info.lua" to "Info.lua". 

- Change line 47 of MySimpleExportServiceProvider.lua to be:

myLogger:debug( "Could not render: " .. (pathOrMessage or "nil"))

("pathOrMessage" should never be nil, but it was, suggesting a bug inside LR.)

[John R Ellis]

I tried the plugin (modified as described above) with a number of very large exports of raw photos (3200 photos, 1260 photos, 660 photos), on LR 11.4 / Mac OS 12.4, with the option Use GPU For Export enabled.  LR didn't crash, though I did get the error "No rendered photo exists on disk. (16)" once, and I got this error once (before I fixed line 47 as described above):

I shouldn't have gotten any errors.  Those errors may or may not be directly related to the crashes you all are experiencing, but it does suggest that 11.4 introduced bugs into Export.

[John R Ellis]

[This post contains formatting and embedded images that don't appear in email. View the post in your Web browser.]

Based on long experience, Adobe will likely not pay much attention to this kind of bug unless many more people report it  or there is a reliable recipe that provokes the problem on Adobe's computers.  Gunther's sample plugin didn't provoke the problem on my computer, and I think that if this bug occurred repeatedly on all or most LR installations, we'd see a lot more reports about it.

My suggestions for how to make it more likely to get Adobe to pay attention: If you experience a true crash where LR exits abruptly and a crash-report window appears, when asked make sure you submit the report to Adobe with the email address you've used in this forum.  If/when they pay attention, Adobe engineers will look up the crash report with that email address.

Also, ulrichf32819305 has reported that disabling the GPU didn't eliminate the problem.  Others here should try unchecking Use GPU For Export and report here whether that works around the bug:

The more details posted here, the more likely someone might be able to post a reliable recipe for provoking the bug.  ("Same exact issue" isn't that helpful, since often the particular details differ.)

[Gunther Wegner]

Hi John, thanks for pointing those things out. I don't think they change anything about the problem, but you are certainly right that they should be fixed. I've just uploaded a new version:

https://www.dropbox.com/s/fiq8roh5v7vggj9/Gunther_Wegner_SimpleExport.lrplugin_2.zip?dl=1

Unfortunatlely I cannot seem to find a way to edit my first post.

[Gunther Wegner]

BTW: This happens with graphics acceleration on and off. I just made a video where I show the issue and how to replicate it:

https://youtu.be/kTiuRw537RE

[Gunther Wegner]

I already submitted many crash reports (in fact every time I got the chance - but it doesn't always happen).

GPU can be on or off, the bug appears either way.

I posted a video below where I show exactly how Adobe and anyone else can replicate this.

[ulrichf32819305]

"More" reports seems to be difficult with a problem more or less happening randomly and kind of regulary only when exporting several hundred pictures.

There's no correlation with the (unchanged) LRTimelapse export plugin, it also happens with the predefined adobe export.

Perhaps there's a special hard-software combination which (doesn't) reproduces the bug.

[John R Ellis]

@Gunther Wegner, in your video, are all the original photos DNGs?  

I'll look at the log file next time, but in my tests with raws, I was successfully exporting up to 3200 raws with your plugin.

[Rikk Flohr: Photography]

setting status to Investigating

[John R Ellis]

@Gunther Wegner, I see that Adobe employee Rikk Flohr has moved your report into Bugs and assigned it a tracking number, which is great.

I ran another test last night with LR 11.4.1 / Mac OS 12.4, with Preferences > Performance > Use GPU For Export enabled.  Using Simple Export, I exported 2000 DNGs converted from the same raw file, about 28 MB each. The export completed successfully, exporting each file, taking an average of 1.05 seconds/photo, which is the normal speed on my computer.  

Further, file SimpleExport.log shows an entry for each of the 2000 exported files -- the plugin was correctly passed each exported file.

But here's the strange part:  The modified dates of the files show they were created on disk at fairly constant rates. But the log file has a near 9-minute gap with no log entries and then a smaller 1-minute gap.  After each gap, there's a burst of activity as the plugin is handed the queued-up exported files to process.

This table shows the rates by minute at which the exported files were written to disk (the File Modified column) and at which they were handed to the plugin (the SimpleExport.log column):

So on my machine, LR is invoking the plugin correctly, but it's getting blocked up, with a huge queue of blocked export requests delayed for 9 minutes before being handed to the plugin.  Clearly not correct behavior.

It may be on those of your exports that don't actually crash, if you let the export wait for a really long time, it will complete correctly.  

[Gunther Wegner]

@John R EllisWhat you are experiencing is most likely related. I'd recommend to do one more test with 5000 images. I'm pretty sure you will also experience it crashing. I don't know where the threshold is, but the less images the more stable the export seems to be but from a certain couple of thousands things go south.

[John R Ellis]

I repeated the test with 6000 images and got similar bad behavior (but no crashes).  This, LR stopped providing exported files to the plugin for 70 minutes!  But eventually they were all provided.

[Gunther Wegner]

@John R Ellisthanks for confirming this.

[John R Ellis]

My educated guess about what's happening: The LR export pipeline creates a separate LR task for each photo being exported by a plugin.  The LR 11.4 changes to the pipeline (to accommodate the use of the GPU) are causing these tasks to get "starved" by the task scheduler, so they're just queuing up for minutes at a time (or longer) waiting for their turn.  This could be as simple as the rendering part of the pipeline not doing a yield() to the scheduler frequently enough.

When hundreds or thousands of these tasks get queued up, perhaps LR sometimes runs out of internal resources and hangs or crashes.

[gian luca burini]

Lightroom classic quits when exporting many files, without generating any errors. Intel I7 PC with 64gbram hard disck c MM2 500gb Free 290 secondary ssd disks.

[dj_paige]

Version NUMBER of Lightroom Classic?

Version NUMBER of your operating system?

Is the problem that Lightroom Classic quits and the rest of the computer runs fine, or is the problem that the computer shuts down and has to be re-started?

How many files is "exporting many files"? (give me a number)

How far into this export do you get? (give me a number)

[gian luca burini]

versione 11.4.1

[gian luca burini]

mediamente 10000 file mai avuto problemi con versione di lightroom precedenti, non c'e un numero di file in cui si ferma

[gian luca burini]

il computer continua a funzionare normalmente

[GoldingD]

hard disck c MM2 500gb Free 290 secondary ssd disks.

On what drive does the catalog reside?

On that hard drive, what is the amount of free space in percent (%) , that is % not gb. Needs to be at least 25%