If you have a freemium LR mobile with no CC subscription, syncing is not possible.
If you have a subscription, then when you log in on Desktop, (top left) it will sync the collections that you have set to sync.
I hope this helps.
Please check the below link that might help you:
I should have mentioned...
It had always synced between devices automatically, as long as it was set to sync.
But Unfortunately when I quit the desktop LR I did not back up the catalog, and now when I open with an old catalog form back in May, all of the current collections are gone of course. I still have the images in the original folders. And also have the collections that were turned on to sync in my lightroom.adobe.com account when I sign in....
I just don't know how to re-sync them back to my desktop...
No you can not re- sync the images from mobile to desktop.
Because the moment you switch the old catalog to new one to sync with Lightroom Mobile, Lightroom will wipe out all the data from mobile application.
May I know what happened to your catalog which was syncing to Lightroom mobile earlier ?
I simply closed the program (quit LR desktop) and did not back up the catalog I was working in. When I re-open the most recent catalog, it does not reflect all the collections and work as the truly recent work has not been backed up in a catalog prior to closing... I know, dumb me, should have backed it up. Will do next time.
But Is there any other way to get that work back with all the ratings?
Can I re-upload each collection from the folder on my desktop Mac and re-create the collection... Will all the ratings reappear?
is there anything I can do? My goal is to have a few recent collections that I was currently working on rating back with those ratings.
I think you have accidentally opened an older catalogue, not the most recent one. Failing to back up a catalogue does not lose the changes (in preferences you see that you have the option to back up on each exit, once a week, or other options, so this should show you that closing without backing up will not lose changes). If your catalogue became corrupted and you have been forced to restore an old backup then that would give you the results you describe.
Why are you opening an old catalogue from back in May? What has happened to the most recent one? If you can locate it, the recent changes will be in place.
Would you please click on File> Open Recent and check whether the catalog you were last working on is listed there or not.
The catalog from May IS the most recent saved one. The one I had been working on yesterday never got saved and all the changes together with it were closed and as i understand lost... That is my understanding.
But as I read your response, I went to use spotlight feature in order to find a newer one... and when I did find the one that was modified yesterday, i tried to open it but got this error message: "The Lightroom catalog named “2015 06 09_Levi 5d” cannot be opened because it is too new to be used by this version of Lightroom. Would you like to select a different catalog?"
What should I do?
I was able to open that catalog with LR CC but only see one collection in it... I am completely confused...
Do you have two versions of Lightroom installed?
Have you tried to open catalog you have recently opened?
If you are getting the error stating cannot open it because its too new that might be possible you are trying to open it in a old version of Lightroom.
I kept searching for the catalogs, using spotlight feature on my Mac. I tried all of the with the extension .lrcat and finally one of them had opened with the collections that I had been looking for. SO I see that Elliek2017 was correct and apparently I don't have to be backing up the catalog for it to be saved (Ha! I did not know that) and as long as I was able to find the right .lrcat, it looks like I can get all my work/ratings back. Now I just need to figure out where is it saving my catalog by default, in case if I close/loose it again, I would be able to find it.... I couldn't see the path... any ideas? Also can I re-open this catalog in newer LR CC and not loose any of the ratings?
Thank you, all!
I am not a Mac person but I believe that if you go to your catalogue preferences dialogue you will see the path of the current catalogue. You can open it from there in Finder. I hope I am correct here as terminology differs between Mac and Windows versions.
In any case, check where your catalogue backups are being placed (on a different drive, by preference) so that you can then find one to restore, should your current one become corrupt.
I'm glad if I helped out.