This is a known issue with Lightroom CC2015.2.1 and our engineering team is currently working on it.
For now, would suggest you to roll back to Lightroom CC2015.1.1 and wait for the next update.
Refer this document to roll back : Instructions to roll back to a prior update version
I would be interested to know- why you think that "Synchronizing" a folder is any different to "Importing" a folder?
So, I have a folder/subfolder like Oregon/Portland which exists with images already in it. I went out yesterday and took some pictures of the Steel Bridge, applied their custom file number and keywording via PM and then moved these images from my workspace to Oregon/Portland via PM, I would want to update the LR Database via Synchronization so that I could then do the preliminary work on the files.
If I went out tomorrow and took some pictures of the Portland Japanese Garden (which is actually closed for about 6 months), I might want to create a sub/sub folder Like Oregon/Portland/Japanese Garden. In this case the folder did not previously exist and I could do a folder import. I believe I use to be able to do a synchronization of the Portland folder and it would update any tiff files added to the Portland folder and also add the Japanese Garden folder with its new images. Doesn't happen right now.
I hope this answers your question.
I think you have experienced the "Bug" in LR-2015.2.1
Until Adobe corrects its problem bugs with the 2015.2.1 release, you may need to modify your methods.
Using Lightroom CC 2015.2.x/6.2.x - When synchronizing a Parent folder that contains subfolders, the synchronize operation will fail with an error message if the Import dialog is not shown before the synchronize operation.
The full explanation is at- Synchronize folder fails with error 'No photos or videos were found to import'
Synchronizing is a quick way to import your images into LR when they exist in a known folder.
The Import dialog does the same but with more options to- re-name, add copyright, add metadata (keywords), apply a develop preset, etc.
And the Import dialog can "Add" new sub-folders and new 'added' images to the catalog just the same as 'synchronize'.
Adobe did a remarkably poor job on this latest release. This is not the only bug that we users have found and/or encountered
hi, I am managing a few catalogues on a 20 tb nas system. There are raw and jpg and a few tiff files. I use the sync folder to help.
PLease deveopment team team return the feature and its functions.