1. You may check whether you have the permission for "Uploading" in the folder.
2. You may check whether you clicked "Cancel Synchronization" before completion of synchronization. Please check whether the files to be synchronized exist at the web side. If they exist, you can clip these wrong files (folders) to the desktop, restart the client side and conduct synchronization. If they don't exist, you can conduct synchronization by clipping these wrong files (folders) to the desktop, restarting the client side and dragging these files (folders) to the list of synchronization.
If your problem cannot be solved by the abovementioned solutions, please contact our online Customer Service (QQ: 800835060). Our online Customer Service staff are happy to help you solve the problem.