We'e sorry that Lightroom gives out an error while syncing images. could you please try the following:
Open Lightroom Classic CC -> Preferences -> Lightroom Sync -> Press alt/option -> Rebuild Sync data.
Lightroom will restart and syncing will reset and there will be no impact on your images.
Let us know how if goes.
Thanks for the screenshot and providing the update.
It seems that the image returning an error while syncing in the "sync activity" menu is causing the sync to stuck.
Could you please navigate to the image in Lightroom library and remove it temporarily?
If that still shows error in the activity menu, head over to Lightroom web: Photo Editor | Online Photoshop Lightroom and delete the problematic image from there.
Let us know how it goes.
1 person found this helpful
Another Follow-up suggestion if the one above does't help:
Refer the solution listed here: Lightroom Classic 7.5: Sync Yields "bad argument #1 to '?' (number expected, got nil)" Error Messages | Photoshop Family… and share the outcome with us.
Ive tried both options and still nothing works. Whats interesting is that once i remove the photo from the library, more errors pop up. I removed about 2 dozen pictures until i gave up. Im not going to remove all 170 of the pictures from my catalog, one by one, to possibly, maybe, get this to work. that just seems silly and not a very good use of my time. Any other suggestions?
Could you please share the Diagnostics log from Lightroom via PM with me?
You can trigger the log via Lightroom Desktop Preferences -> Lightroom Sync menu and when you hold down the Alt/Option key you will notice a generate diagnostic log button
Once the log is generated, you can forward it using your mail client and download the log file. Attach it to a Dropbox link and share it.
PMd as requested
1 person found this helpful
We checked the logs and it seems that you have a similar issue as listed in Lightroom Classic: sync problem: bad argument #1 to '?' (number expected, got nil) | Photoshop Family Customer Community
Our engineers are tracking this issue in the above discussion. Please share your issue details in the discussion so that they can look into it.
I have had the same problem for months and now none of my iPad Pro edits will sync to the desktop (Lightroom Classic version: 7.5 [ 1186149 ], Windows 7 Business Edition Version: 6.1.7601) although they sync to the cloud and show up on the web.
Lightroom shows that it is "Syncing 25 photos" at the moment (this number varies), the Catalog panel does not show any sync errors and there are no errors shown on the webr. The Lightroom Sync tab in preferences shows stuck photos with the bad argument #1 to '?' (number expected, got nil) error and about 18 unidentified files that have been pending since sometime last August and which do not seem to cause syncing to get stuck.
I have tried purging the cache on both iPad and Desktop, signing out and signing in of my Lightroom account on both iPad and desktop, rebuilding Sync Data and restarting, and removing collections that had photos which were causing sync errors, removing the stuck photos from All Synced Photos, removing (but not deleting) the stuck photos from my catalog and more. Editing a photo or group of photos sometimes works for those photos (adding metadata doesn't work as often as changing a Develop setting) . I have even tried wholesale deletions of files that are in All Synced Photos but not in collections I'm currently working on. Rebuilding Sync Data and other solutions remove the stuck photos but more immediately show up. Almost all of the stuck photos have not been edited recently.
I would prefer not to lose all the edits I have made on the iPad (both metadata and adjustments). I've been following several forum threads without finding a solution. May I send you a diagnostic file to see if there is a solution I've missed?