Ok, I think I see what is going on. When you open Adobe Elements Organiser, it will open the directory where your media files are stored and keep it open. Now TImeMachine comes and wants to make a backup of your system. It will create a snapshot of your Mac's disk, like a frozen point in time, and mount it on /Volumes/com.apple.TimeMachine.localsnapshots/Backups.backupdb/blahblahblah. Abode Elements Organiser still has the directory open, which is now frozen as part of this snapshot. Now you import some new files from your camera. They get copied from the camera into your media file directory, but it is the directory on the live harddisk, not the frozen copy captured in the snapshot. The files are copied onto your harddisk, and the catalog is updated with the new filenames. Organiser now looks for these new files you just imported, but it is referring to the open filehandle on the directory that is now frozewn in the snapshot. Organiser complains that it can't see the new files in the directory it has open (since it is referring to a frozen snapshot taken before the files were copied from the camera) and then it complains that the files cannot be found. In the error message, it tells you the name of the directory it is looking into, based on the open filehandle it has, and this refers to the frozen snapshot that TimeMachine made of your harddisk, so you see in the error that it cannot find the file in the open directory at /Volumes/com.apple.TimeMachine.localsnapshots/... etc.. If you close Organiser and reopen it, the catalog is still referring to filenames based on the snapshot name, and so the files are still "missing". However, if you close Organiser, and stop the backup, then reopen Organiser, the snapshot directory is gone, and Organiser will try to reconnect your files by searching on the live harddisk. This time it finds the files, and the file connections are rebuilt. So, what can we do? Basically, we want to store the media files on a disk or partition somewhere where TimeMachine won't be creating snapshots to back up the filesystem. Excluding the Adobe Elements directory from timemachine backups won't help, because a snapshot impacts all files/directories on the filesystem, regardless whether TimeMachine is going to make a copy or not. So, easiest solution would be to store your media files on an external drive, and don't use TimeMachine to back up that drive. Instead, use the backup facility of Adobe Elements Organiser to do your backups to another external drive. You could probably also create a new logical APFS Volume on your internal harddisk, sharing the same container as your existing volume, and don't do TimeMachine backups on that second volume. This means no snapshots on the Adobe media directory, and so no problems to use Organiser while TimeMachine backs up your main volume. When I find some time I might give it a go and see if it works as I expect.
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