Is this still a known bug, and is there a work around?
As you read, the disastrous LR CC 2015.2 / 6.2 release introduced problems file folder synchronization. However, the 2015.3 release fixed those problems (or at least, most of them). I don't recall seeing any similar reports for 2015.3 or later. Sorry I can't be of more help -- perhaps someone else will correct me.
This added thousands of files to existing folders on the 4Tb HDD which already exist in my Lightroom catalogue, which is ordered in Year then Year-Month order. I assumed that I would then just right click on my main pictures folder on the 4Tb and let it synchronize all the year sub-folders to pick up the newly copied images there.
If the goal is to move photos that have already been imported into Lightroom from one drive to another, then synchronization will not work. The photos are already in Lightroom, and so they cannot be imported or synchronized into their new location. So if I'm understanding you properly, I would say that this is the expected result from synchronizing folders.
The proper way to move photos to a new drive, photos that have been previously imported into Lightroom, is given in part 2 of this document: Adobe Lightroom - Find moved or missing files and folders
HI DJ - thanks for your response. No, the images i copied over to my 4Tb drive were not already in Lightroom, at least not in the catalogue as associated with the 4Tb drive, so having been copied manually outside LR my understanding (and all previous experience using LR since it's first beta) was that the Sync would then add them into the catalogue and register them as images on the 4Tb drive.
I'm still not clear.
I don't understand "not in the catalog as associated with the 4TB drive". Do you mean you have a specific catalog for just one drive and a different catalog for other drives? Or do you mean you have one catalog for everything and the photos have not been associated with the 4TB drive in that catalog?
If the latter, you have one large catalog for all of your photos, then I continue to state that my earlier explanation holds, and you cannot use synchronize to move photos from one drive to another.
OK I'm not being clear. Let me try to explain it better :))
If we look at the screengrab in my original msg, we see folders ordered by year on the 2Tb drive. These are all in my (only) LR catalogue and accessible in LR.
I bought a new 4Tb drive, and as the screengrab shows, I have a similar set of folders on that, and these folders and the lesser number of files in them are also in the same LR catalogue and accessible in LR.
So my aim is to copy ALL the photos from my 2Tb drive folders into the corresponding 4Tb drive folders, which I did using an external file copy utility. The copy worked - the folders on my 4Tb drive now have lots of new copied images in them, but of course LR doesn't know about them yet as I haven't done a Sync.
Past behaviour would have seen LR update the catalogue and make the copied images on the 4Tb drive accessible in LR when I right clicked on each of the 4Tb year folders and selected Synchronize Folder. When I do this however, it seems to go through the process, with the normal progress bar running in the top left corner of the screen as expected, but then at the end it just reports "No images found to import" and I'm left still not able to see my copied images in LR in the 4Tb folders.
Still cant see my copied images on my 4Tb drive - any more ideas - anyone??
Ok, I understand your situation now. However, you have misunderstood what Sync does.
You cannot move photos to a new drive that have previously been imported into Lightroom using Sync. I stated the proper method in an earlier reply.