When I move a folder (drag and drop) to new location on same disk, it doesn't show in the new location and shows as missing at the original location.
Restarting LR seems to solve the issue, but is not great when I'm organising work!
Are you doing this move inside of Lightroom, or in your operating system?
As an aside, and a bit of a moan, I've also seen the issue where I cant see a folder that I know is there. Synchronise doesn't work and if I try to re-import the images lightroom tells me they are already in the catalog, but I cant see them? If I use finder I can see the images, just not in lightroom. Also seen it directly after import, where the folder doesn't show, but if I click on an image from 'previous import' and select show in finder, it takes me to the directory that doesn't show. I've done some brief searching of these issues but just see threads with condescending replies advising people they must have duplicates elsewhere in their library.
All of this sounds like you are importing (accidentally) by copying the photos to a different folder than the one you want. If that has happened (and we all make mistakes sometimes) then Lightroom will not show you the original folder, it will only show you the folder where the photos have been copied into. IMPORTANT CONCEPT: Lightroom is not a file browser. It does not have to show you the folders that you know are there. IMPORTANT CONCEPT: If you have accidentally copied the photos to a different folder at import, then neither Synchronize nor Import will fix the problem. Synchronize and Import are working properly in this case. You have to find the photos in your Library Module, and then you can perform whatever task you want in Lightroom.
I'm moving the files in LR and I understand the difference.
IMPORTANT CONCEPT: I've been using LR for many years and understand how it works. I'm not using it as a file browser - I'm using it as a library. The images are not elsewhere in my library, i've checked. But I feel this could be a distraction. The simple folder move is my current issue.
Here's a fun example of this kind of issue. I'm managing some old neg scans and have renamed this folder (2016-02-22 Avoriaz).
Folder is now greyed out and shows 0 files. However, when you click on the folder the images are there and when selecting 'show in finder' you can see they are all there. Just that the folder shows 0 files and is greyed out. Restart of LR resolves the issue??
When you complain that you can't see a folder that you know is there, then you are expecting LR to act as a file browser, which it is not. Showing me the folder in your operating system is irrelevant again indicates that you think LR is file browser. LR thinks there are no photos in that folder, and will not show you photos in that folder unless you take some action to point Lightroom to that specific folder.
Please go ahead into your Library module, and click on All Photographs, and then using the Lightroom Filter Bar, search for one (or more) of these photos that are supposed to be in that folder by File Name, you will find them in your LR Library Module, and they will be in a different folder than the one you think they should be in. Please give this a try.
Sorry if i'm being curt but did you read anything I wrote? I've renamed a folder and it now shows 0 files? But they are still there and its fine after restarting LR.
If renaming and moving folders within LR is asking it to act as a file browser, and this doesn't work, then its no good as a library management tool.
Not sure if you work for Adobe or are an 'ACP' or regular Joe like me, but your default position should not be user error, its only one option. I see this all over the forums and its annoying because it just assumes that there isn't a problem with the software. LR isn't perfect and has been going downhill for a number of years e.g. I have to use a 3rd party app (freeware!?!) to edit because LR takes so long to render 1:1 previews.