LrC "Lightroom mobile sync" caught mulching my photo archive

Summary of bug: Changing the path to where LrC stores synced photos, under “Settings > Lightroom Sync > Specify location for Lightroom’s synced images” caused LrC to arbitrarily move photos out of folders under which I had organized them by date into the “lightroom mobile sync” folder, on its own.

Temporary fix: unchecked “Specify location for Lightroom’s synced images” and restarted LrC. 

Detailed report and context indicating possibly related issues:

After copying my LrC photos spread across multiple HDDs to a single new larger external HDD and repointing the library to the new path, I would get an error message every time I started LrC saying, “Lightroom cannot write to the following directories. Until this problem is resolved, syncing from Lightroom may not function correctly.” The path was on of the old drives I migrated my data from, “/Volumes/Yellow [4TB]/lightroom mobile sync” to options to click: “show in finder” and “OK.” In my case, “Show in Finder” was greyed out so my only option was to click, “OK.”

Yet “lightroom mobile sync” was moved to the new drive and showing up in my list of folders in LrC.

“lightroom mobile sync” is not a folder I created. It seems to have been created by LrC for photos that Lightroom on iOS/iPadOS automatically copies from the Camera Roll on those devices. I had by then turned that feature off and deleted most of the photos in the lightroom mobile sync folder.

Therefore I could not figure (a) why LrC did not know were to find the path for the new location and (b) how to point it there, and Adobe did not indicate how this could be done in its error message, because as we all know, their software design is bloated and brittle, so prone to multiple failures, and ungraceful when it inevitably fails and really difficult and time-consuming to diagnose and fix afterwards.

The following was witnessed by Adobe technical support under case number,  ADB-28388602-Y0Y5 via remote control:

It turns out that the multiple Adobe tech support agents that I trouble shooted this problem with did not know that the path for “lightroom mobile sync” could be specified in the settings, after me asking them if this could be done several times. I only discovered this could be done by accident, while troubleshooting another possibly related sync issue with an Adobe agent.

It was indeed possible to specify this path under “Settings > Lightroom Sync > Specify location for Lightroom’s synced images.”

However when I specified the new path to lightroom mobile sync, this folder from which I had already deleted most of the photos started to fill up with new photos, and not photos that I took with my iPhone’s camera but some of the first photos I imported into LrC from my A7RIII in 2018!!! And it turned out that Lightroom was moving these photos out of the subfolders where I had carefully organized them by date, into “lightroom mobile sync,” leaving some source folders completely empty!

As a temporary fix the tech support rep turned off the option to “Specify location for Lightroom’s synced images” and restarted LrC. 

Now I am left with half of my images from 2018 disorganized and possibly missing. I have no idea, because it’s going to take some time for me to determine precisely what happened.

I don’t understand how or why it happened. I only know that I did drag and drop random images out of those sub-folders and that this should not have happened in the first place. 

I have a backup of my “2018” folder on my NAS and can confirm that the images are organized as expected in that backup. They were definitely moved by Lightroom, without my authorization, as witnessed and hopefully documented by the Adobe tech support rep. 

But the good news is that after destroying the meticulous organization of my photo archive, LR on iOS/iPadOS now starts up normally. Yay!

For further context:

In the past month I have migrated from a 2017 Intel Mac Pro to an M1 Mac Pro and a week ago, I migrated my LrC photo archives, which were spread across multiple drives to a new, faster, larger external SanDisk Pro HDD. These are backed up locally and in the cloud.

I have been having a number of (seemingly) sync related issues with LrC and Lightroom for iOS/iPadOS for over half a year that Adobe technical support have never managed to help me to completely resolve. Symptoms include: 

• LrC taking an extremely long time to sync edited images across deices or even update local thumbnails after editing them in LrC; 
• LrC taking forever to sync thousands (typically between 3000 and 4500) of images after leaving it on for days to do so;
• LrC losing track of where arbitrary images are stored, even though they remain in the specified path on the drive;
• LR mobile not starting up and giving an error, “Lightroom detected an issue, please quit and restart the app to resolve. Error code: 19650929,” when I start it up.

This also included the loss of thousands of images that I moved between hard drives using LrC, somehow not ending up actually being moved to the new location and without warning of an error from LrC, leading me to delete the directory where they were still stored on my old drive, and the loss of my photos, a loss I did not discover until long after a backup of the drive had expired. Of course Adobe claimed that this was impossible and the error must have been on my part, not LrC, and how can I prove otherwise?

Bottom line, I can’t trust Adobe LrC to manage my photo archive and neither should you! It isn’t designed to be robust or transparent and graceful when it fails in its central task, and thus poses a grave danger to the security of its users precious data, a privilege for which Adobe greedily charges an overpriced subscription fee.