I am currently using Lightroom CC 2015.6 but I have been having the same issue with all my older versions.
If I check to synchronize a library folder, Lightroom thinks that several files need to be synchronized.
I usually classify my folders by year and subfolders by dates.
The strange thing is that there are indeed no new files to be synchronized and when Lightroom finishes its synchronizing procedure it doesn't find anything to be synchronized. It is not a big problem in itself but sometimes it simply makes me loose time in thinking that there are files to be synchronized and I am also afraid that my catalog could be corrupted which could eventually become a critical problem?
Anyone have been having the same issue? If Yes? Have you been able to solve it?
If your catalog was corrupted, then it wouldn't open in Lightroom. So you do not have catalog corruption.
Nevertheless, since you are worried about this, you should be making regular and automated backups of your Lightroom catalog; and you should be using the built-in Lightroom catalog backups procedure, and when you use this to make your backups, you need to check the box that says Test Integrity Before Backing Up and also check Optimize catalog after backing up.