I didn't need any of the new cameras, so it wasn't a big deal for me, but copying and pasting develop settings is a big part of my workflow.
Also auto synch in the develop module didn't seem to work either, but rather than do a lot of testing I just reverted to 8.2
I was working on Canon CR2 raw files and was trying to develop a group of four images identically for image stacking. Everything is back to normal since I went back to 8.2.
I’m in the Develop module. I adjust one image. I hit the button in lower left “Copy..” I make modifications if necessary in the popup window. Then I select multiple photos, usually immediately following the first one. Then I hit the button in lower left “Paste”. And nothing happens. Sometimes only the first image gets the pasted settings, sometimes none. Usually there is a progress bar saying settings are being pasted but it is only very brief.
The only way I get the Paste function to work is one image at a time. I cannot do multiples.
I’m using Lightroom Classic CC 8.3.1. I have the Adobe Cloud account. I’m on macOS High Sierra v 10.13.6. Mostly my images are Nikon NEF 36 MB, but sometimes JPGS.
This problem has been with me for years now, several upgrades ago, but it is only now I decided I better address it. Would appreciate how to fix this bug, thanks.
Develop settings via Copy/Paste can only paste to more than one image if you are in the Grid view. Then you invoke the Paste via: Photo>Develop Settings>Paste Settings [Shift][CMD][V]
As Yves points out, Synchronize would be the correct function to use in Develop when multiples are selected in the Filmstrip.
Hope that helps!
A workaround is to right-click one of the selected filmstrip thumbnails and choose Develop Settings > Paste Settings.
The current design was intended to avoid accidentally changing selected photos while not realizing more are selected. But I think it has caused more confusion than it avoided, and encouraging users to turn on Auto Sync (as is usually done in the forums) has itself created significant problems for users. Having Copy/Paste, for example, accidentally change all selected photos is a problem; but leaving Auto Sync turned on by accident and having all subsequent commands silently change the photos is worse.
This mess could be improved a couple of ways. When the user is in Loupe view and applies any command that affects multiple photos, LR could:
1. Pop up a dialog that warns, "You have multiple photos selected, and they will all be changed Proceed?  Don't show again." If the user didn't want to apply it to all the selected photos, she can simply unselect them.
2. Ask the user if the command should be applied to the current photo or all selected photos. This is what right-click-Metadata Presets does:
Who knows why this particular command does this but none of the others -- must have been the phase of the moon.
I realize it's highly unlikely that this will ever change at this point. But I think we should stop suggesting to users who encounter this confusion to use Auto Sync. Applying the command by right-clicking the filmstrip is much safer (when applicable).