Could you try to remove the sync.lrdata file and restart Lr Desktop. Removing the Sync.lrdata might fix whatever the issue is. Or, at least, might trigger it to occur again. So remove the Sync.lrdata, start Lr Desktop, and then try to remove a photo and in case you still run in to this issue ... create at this point a Lr Desktop diagnostic log which can hopefully provide some clues. You can find the sync.lrdata file here: On Mac it's at /Users/<user>/Library/Caches/Adobe/Lightroom/Sync Data/Sync.lrdata On Win it would be at C:\Users\<user>\AppData\Local\Adobe\Lightroom\Caches\Sync Data\Sync.lrdata You can trigger the diagnostic-log via LR Desktop preferences -> Lightroom Mobile and when you hold down the alt key you will notice a generate diagnostic log button Hope this helps. Guido
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