If you exit or quit the desktop app on your current computer, changes to files on this computer are no longer synced to other computers, and changes from other computers are no longer synced to this computer. Sync does continue between the cloud and other computers running the desktop app (that is, between the cloud and your other computers, and those of people you are sharing files with).
When you restart the desktop app on your current computer, the files are synced with those in the cloud.
If restarting sync causes a file conflict, you see an error icon overlaid on the app icon in the system trap. Select Sync Problems from one of these menus to view any errors.
Right-click in the notification area (Windows) or in the menu bar extras area (Mac).
Click and then click .