I was able to get this working but it was very painful...  Adobe did not help and said I would have to create a new catalog and re-edit and tag 30K pictures...  First I copied my files from my nas to a harddrive and tried to find missing pictures on the local drive and it still did not solve the problem.  The issue seemed to be residual data from the PC so it could not change the root of the folder.  I discovered I could find missing photos on the harddrive but not the upper folder.  The good news is that if you find a missing photo, it would pull in all the photos in the directory and all subdirectories.  However, it would start a directory at that level.  So you will loose the directory structure you had before...  For example, if you have travel and the two subdirectories france and italy and no individal picture under france, just the directories.  I went into france which had pics and did a find on one of the folders.  I created a france folder at the root level.  Then I went to italy and did a find and it created an italy directory.  The good new if found all the files under each directory.  But the travel folder was lost.  I would recommend not moving or adding folders until you have found all your pics on the hard drive.  I hope that is clear and helps someone... ... View more

I am not sure I understand how mapping the NAS to a drive on my PC will help.  The problem is on my MAC.  I have verfied there is no access issue as I can import from the NAS if I create a new folder.  The mount points for the NAS are different between the PC and the MAC.  I believe the info about where the mount point is stored in the folder attributes, and when moved to the MAC it is still pointing to the PC mount point.  So, I have no issue navigating to the directory, but when I try to update the location of fails because the mount point for the NAS stored in the folder is wrong. ... View more

Thank you for sharing that progress.  my catalog is still on my PC as well, but my NAS no longer shows up under Network on my PC, not sure why that is but that means I cannot currently map it to a drive...  Need to work that out first. ... View more

thank you for the update...  The catalog is stored in the Mac filesystem (was previously on the Windows filesystem).  I will check out the resetting of the preferences.  This issue occurred moving from Windows to Mac, so I do not believe mapping is an option, I did try one other thing on the Mac, I attempted to add a new folder and it had no issues with the same folder name and started searching for photos, but it was going to import them so I cancelled it.  So going to the same folder to import works fine, but finding a missing folder for that same folder does not work.  Thank again for the info. ... View more

So, it sounds like that problem was not resolved in 11.5...  I also have a crash related to opening video files, but that is not as crtical.  I guess I will have to export all my pics and create the slideshow under another product... ... View more

I am already at 11.5 ... View more

Concerning backups, something could happen to Adobe servers.  Just like if you had your pictures on a local hard drive or NAS.  Unless Adobe is stating they do daily backups and a way to restore files, you have no backups. ... View more

Thank you for the response.  Just to make sure I understand...   Do I have to drag each folder separately?  or just the top level and it will keep the directory structure in LR classic?  Then I can migrate the catalog to CC and it will maintain the folder structure?  Not sure what is involved in "drag the Folders into Collections"... ... View more