Collection Moved to Subcollection, Now its Empty!
I had a series of collections with each's contents including different search results from different stages of a systematic review. Somehow my 4CE folder disappeared. After checking to see if I accidently dragged it to a nearby folder, I found it in a folder starting with 5CE yesterday. But when I looked to see if the 4CE folder still contained all its contents, it and all of its sub-collections were empty! Please help ASAP! I'm on a deadline too! :-O
Note also the View → Show Items from Subcollections setting, which determines whether a parent collection shows all the items from its descendant collections.
If you think you're still missing something after that, and this just happened in the last day or two, you may be able to restore a collection from one of the automatic backups. See the specific instructions for restoring a deleted collection. You still might need to remove items from the trash after syncing.