P: Synchronize Folder hangs

[FeedbackCommunityMember]

Lightroom Classic CC, latest version, freezes when I use "Synchronize folder" and have the "show import dialog before continuing" option selected. (Not only does it freeze but it ends up using a ton of CPU, more than 200% per Activity Monitor, and the fans start going like crazy.)

Lightroom synchronizes the folder just fine when I DON'T have that option selected, but I need to be able to use that option. The problem occurs whether or not the "scan for metadata updates" option is selected.

I'm on a Macbook Pro, latest version of Mojave. In Lightroom, the issue occurs for me in the latest version of Lightroom Classic CC. Per a different forum post in which someone solved their problem by downgrading to v 7.5, I tried that but the problem remains.

I did NOT have the problem in Lightroom 6 (from 2015), which was what I was using until just recently when I got a new computer and needed to upgrade my OS. I'm still trying to get back up and running with Lightroom on the rebuilt system, and this problem is keeping me from moving forward.

I've tried resetting preferences to no avail.

This is a folder with a lot of images (more than 15,000). Do I just need to give it all day to run for the first time or something? There are only 26 images in the folder that have changed.

[tmickow]

I don't know what your workflow is, but running a synchronize on a folder of 15K+ images just to get 26 of them updated probably isn't going to be terribly efficient.  When you tell Lr to show the import dialog box, it's going to look at all those files, pull up thumbnails, look for duplicates, etc.  If I were you, I'd consider breaking things down into smaller buckets going forward.

[Jerry Syder]

I do get this as well(Win 10), even when syncing a folder with 20 images. This has been happening since version 8 I believe. See below video. n.b. that LR does not recover from this state. I have to kill the program and do it the way that HB mentions it works(not use the import dialog). This folder has only 129 photos. 

[FeedbackCommunityMember]

Thanks much for the fast reply, Tom. I have it set up that way because I'm using the Pin4Ever browser extension to back up Pinterest pins to my computer, and the way that works is everything has to go in one folder. It doesn't have an option to organize it differently, and if I were to put those photos into different folders, it would cause the extension to think the photos didn't exist.

On Lightroom 6 (2015) things worked fine with this workflow, even though it was slow. I.e. things would show up right away in the import dialog. It would take a while to process, granted, but it didn't freeze up, and I could just do other things in the meantime. This was with the same number of photos and same general proportion of them that changed. 

On these more recent versions of Lightroom, it is a totally different issue. The problem is not that it is slow but that the program completely freezes up, with nothing happening at all (no thumbnails ever show up)  and I have to force quit the program, which is a very different matter.

Is there anything else I can try?

[Rikk Flohr: Photography]

A Preference File will survive a Lightroom uninstall/reinstall. Sometimes weird behavior is corrected/cured by resetting the preferences. 

Reset Procedure:

1. Close Lightroom.
2. Hold down [Alt/Opt]+[Shift] while restarting Lightroom. 
3. Overwrite the Preferences when prompted by the dialog.
4. Close Lightroom.
5. Restart Lightroom.

Does the behavior continue after resetting the preferences?

If so, tell us about the drive you are using where the folder you are attempting to synchronize resides. 

If you chose a different drive and folder does it work?

[J Isner]

I have exactly the same problem.  I have had the problem with all versions of Lightroom Classic since I upgraded to Windows 10.

[Samoreen]

Hi,

I have the exact same problem as HB on Windows 10 Pro 1909 / LR 9.2.1

The problem started when the number of files in the folder reached about 2000 photos. Never seen that problem before and there's no problem when synchronizing other folders.

See https://feedback.photoshop.com/photoshop_family/topics/cannot-synchronize-folder-after-reaching-abou... .

Just before I reached that 2000 images limit, the synchronization of a few additional images was very quick. So it's not a performance issue.

[Facebook 3]

https://www.facebook.com/profile.php?id=100035370891116

[Facebook 3]

https://feedback.photoshop.com/photoshop_family/topics/5000000 https://www.facebook.com/profile.php?id=100035370891116

[Samoreen]

Hi,

I created 2 sub folders containing about 1000 images each, that is, I split the above mentioned folder in 2 parts. The problem disappeared. I moved back all 2000 images to the original folder. No synchronization problem while the folder now contains exactly the same images as before.

Yet another Lightroom mystery.

[Samoreen]

Problem back today after trying to synchronize a few files. Details in the above mentioned thread.

[allenk45749118]

I am seeing the same problem with Lightroom Classic 9.3 and Windows 10.0.18363.  The folder in question is not very large -- 600 photos.  Turning off  "show import dialog"  fixes the problem.  One additional tidbit... a peculiar item appears in the folder hierarchy in the import dialog, just below the folder being synchronized.  Looks like a spinning circle timer, but it's only a partial circle and is static.  BTW, this folder has no sub-folders.

[Samoreen]

> One additional tidbit... a peculiar item appears in the folder hierarchy in the import dialog, just below the folder being synchronized.  Looks like a spinning circle timer, but it's only a partial circle and is static.

Yes, this can be seen in this video :
https://www.dropbox.com/s/wekrmwvwxgwubr2/FolderSyncBug.mp4?dl=0

[Rikk Flohr: Photography]

Thanks for the updated information. The team has opened a ticket to look at this. 

[Henkki Zakkinen]

Same problem here. Complete standstill at 90-91 %. No dialog coming up.

Lightroom Classic version: 9.3 [ 202005281810-476e492c ]
License: Creative Cloud
Language setting: en
Operating system: Windows 10 - Home Premium Edition
Version: 10.0.18363
Application architecture: x64
System architecture: x64
Logical processor count: 6
Processor speed: 3,3 GHz
SqLite Version: 3.30.1
Built-in memory: 16367,0 MB
Real memory available to Lightroom: 16367,0 MB
Real memory used by Lightroom: 2176,1 MB (13,2%)
Virtual memory used by Lightroom: 2273,8 MB
GDI objects count: 766
USER objects count: 2767
Process handles count: 3603
Memory cache size: 62,0MB
Internal Camera Raw version: 12.3 [ 493 ]
Maximum thread count used by Camera Raw: 4
Camera Raw SIMD optimization: SSE2,AVX
Camera Raw virtual memory: 30MB / 8183MB (0%)
Camera Raw real memory: -1182MB / 16367MB (-7%)
System DPI setting: 96 DPI
Desktop composition enabled: Yes
Displays: 1) 2560x1440, 2) 1920x1200
Input types: Multitouch: No, Integrated touch: No, Integrated pen: No, External touch: No, External pen: No, Keyboard: No

Graphics Processor Info:
DirectX: NVIDIA GeForce GTX 970 (26.21.14.4120)

[Henkki Zakkinen]

Synchronization does work if I uncheck the "show import dialog before importing" option.

[Samoreen]

It seems that the problem doesn't show up when I discard the previews before synchronizing. This is consistent with the non-occurrence of the bug when bypassing the import dialog during synchronization : the previews are not needed in that case.

If anyone can confirm...

[Samoreen]

Problem not fixed in version 10.

[FeedbackCommunityMember]

Still not fixed in V10.11 

[Samoreen]

Confirmed. Unfortunately. Very annoying bug.

[FeedbackCommunityMember]

My culprit was android phone connected to PC via usb. When I disconnected it, import dialog and sync folder started working again.

[Stephen Byerley]

Same problem here on MacOS. This is extremely frustrating.

[E33WW2DTDN]

resetting preferences didn't work for me

win 10

lightroom classic 10.4

using folder on external USB drive

[Lenanard]

I have excactly the same problem (Windows 10, LR 11.5).

It never happened before, and now after several successful synchronize with show import dialog, it happened suddenly. Tried to restart LR, Windows, but now I can only synhronize without the show import dialog. All was ok as long as the folder had less than approx. 2000 files.

Bernard

[Samoreen]

More details about this persistent issue...

I had a folder with about 3000 images. The problem appeared after I added the last few hundreds. I split the folder into multiple subfolders, each one containing no more than 600-700 images (same images, no change). The problem disappeared.

1. The problem is not tied to any technical issue with one of these images but rather to the number of images being processed (that is, compared).

2. For each synchronization, I only added about 20-30 images to the initial folder. All the images already present had been already processed and their preview was present. So, it shouldn't be a memory problem since only a few image previews have to be generated. And I have a lot of memory available on my system.

Hmm! Looks like a stack overflow problem. I guess that LR has to compare the new and already present images in order to detect duplicates and files of different types having the same names. I don't know how the comparison is being made but since LR crashes when doing this, I suspect a bug in the image list management.

Well, now back to my old obsession about LUA (the infamous language being used to develop the LR UI). I doubt that LUA is very appropriate for managing big lists the classical way by dynamically allocating memory for each item. I suspect that pre-dimensioned arrays are used to do this. And under certain circumstances, these arrays are probably too small and the code is not checking this. Otherwise I don't see why the synchronization process fails only when the number of images exceeds a certain limit (which appears to vary a lot depending on the user's system).

Just a guess.

[Mike_Philp]

A big thank you to Rikk Flohr. I had a problem where the "Synchronise Folder" function would cause Lightroom Classic to hang which was very irritating. I came across Rikk's suggestion the reset the Preferences and "bingo" problem has been solved.