I recently discovered that two of my folders, Documents and Pictures, apparently contain no items, although previously they did. When I searched for a particular item using File, Find, it appeared to be in the Pictures folder and I could double click it and open it from there. I've forgotten which item it was.....
On my El Capitan partition all appears to be normal.
Not that type of hidden Eric. The ones on this thread are system files which it's advisable not to mess with - which is why they are hidden. The factor which hides them is that all their file names start with a full stop so unless your folder name started with one, it wouldn't be hidden as here.
Now, why have your files ceased to show? Can you check your El Capitan version to get a few more file names and see if you can find them in the Sierra partition using File,Find?
Yes, thanks Mick, I'd guessed it was a new fangled complicated thing but thought I'd utilise the thread anyway.
I noted a file in the El Capitan partition called Full House, in the Sierra partition tried to get it with File, Find, and it said it was in the Movies folder; it isn't. (but that 's where it is in the El Cap.)
Double clicked it in File, Find, and it opens...
I can't be certain of the key combination used in Sierra but when you see it in File, Find, try pressing the Command key to see if it shows you the path to the file in the bottom of the window. Or Alt?
I have found another use for this tip from Eleanor.
After copying approx 1TB of data from one external HD to another, I did a check to see if the copy was successful. However the 'Get info' window showed a size difference at the top level. Checking the size of each of the 6 folders gave a perfect match. Where was the difference?
Using <Command><Shift><.> showed the hidden files. The difference in size was due to the .trashes folder being different. Mystery solved.
An online check confirmed that .trashes is part of the wastebin system, which was not, and need not be copied over.