TRATRA wrote: @Richard.Taylor : I got an email stating you had posted a reply. I can see it when I follow the link, but it's gone when I log in to answer. I have now idea how that can happen.
You can go here
https://discussions.apple.com/community/applications-services/photos
and then find your post. Or, you can just Google the title and it will come up.
You say : "Am I misunderstanding? A Photo Library cannot work if it's in iCloud-- the Library must be local. The normal place for a Photos Library is in the user's Picture folder. It can be located in other folders, but not the iCloud Drive folder."
This is confusing. I have had my System Library on iCloud for years now and never had any problems, until now.
Here's the explainer from Apple : https://support.apple.com/en-us/108782 it also explains about Optimize Storage.
It should say "iCloud Photos keeps [a copy of] every photo and video you take in iCloud."
There is a Photos Library on your Mac, on your Phone, on your iPad, and at iCloud.com. Photos uses iCloud to keep all of those exactly the same. Optimize may not keep full sized originals local, but when you go into edit mode it downloads them from iCloud.com. Often you see a little circle on the lower right filling as it downloads. Once an original downloads, it remains in your local Library until space is needed or Photos is pretty sure you're through with it. What happens when you go into Edit mode with non-videos?
In case you didn't see this:
the Library must be local. The normal place for a Photos Library is in the user's Picture folder. It can be located in other folders, but not the iCloud Drive folder. Many people operate with their Photos Library on an external drive, but in that case the external drive must be formatted in either APFS format or Mac OS Extended (Journaled) format. The drive must be connected directly to the Mac by cable, not networked, clouded, NASed, etc. If we use iCloud Photos, then our Library is copied to iCloud, but that doesn't affect the local operation.
So, where is your Photos Library located? Is it in the Pictures folder or on an external drive? If it's on an external drive how is that formatted?
This is what a video in edit mode looks like for me-- how about for you?
