This solution works indeed, but unfortunately One Drive then downloads all files on my hard drive (which has not enough capacity, that's also the main reason of using One Drive in fact ...).
Um, the main reason I use OneDrive is as an automated backup in the cloud; I would never, ever trust it to be my main content repository. I also use two external hard drives for additional backup, though I only make fresh EHD backups occasionally, just for
peace of mind.
I get the same problem as everyone else with thumbnails not appearing for images and video, but only for files stored on my main hard drive and backed up in OneDrive. Thumbnails for content held on my C-drive but not in my OneDrive folder are all fine. I
only use simple file extensions like .jpg, .mpg and .avi, with the odd .bmp or .mkv or .mov, and none are showing thumbnails if they are held in OneDrive.
Somehow holding files in the OneDrive folder is stuffing up Windows Explorer's ability to analyse an image or video and display it as a thumbnail: when I navigate to a folder holding images, I can see the computer attempting to load thumbnails - they appear
for what must be milliseconds, then revert to the default image. I can also sometimes see thumbnails if I choose View > Medium-sized icons or Tiles or Content, but not Small, Large or Extra Large, which are of course the most useful ones.
I have tried deleting my thumbnails index and the two methods described in previous postings on this thread to instruct Windows Explorer to show thumbnails rather than icons. My copies of Windows10 and OneDrive are both bang up to date. I've also tried adding
tags to images, which I've seen suggested somewhere else: this does usually somehow force Explorer to display the thumbnails, but if you navigate away from the folder and come back, the thumbnails fail to reload.
The *only* approach that works for me is to to switch off the Files On Demand service. This forces OneDrive into a rapid session of "downloading" (I use inverted commas because the content is all held on my local drive
already). I could see all my files having the tiny blue "refresh" icon added to them, before being replaced by the green tick that says "task done". This only took a couple of minutes, and miraculously, there were all the thumbnails!
However, as soon as I switched Files on Demand back on, the thumbnails disappeared again.
Like so many other people, I have to ask "**** is going on?" Does Microsoft have *any* idea why the interaction between Explorer and OneDrive should be creating this problem for so many people?
I haven't tried moving my entire Onedrive-protected content set to a different drive as suggested elsewhere on this thread: it seems like an awful lot of work to set up a partition, disconnect OneDrive, then move it
and ask OneDrive to re-upload everything again, and without step-by-step instructions, I'm worried something will go wrong.