If ShareSync shell extension is missing (there are no overlay icons in my ShareSync folder):

  1. Make sure ShareSync is running and is present in tray. Icons are only shown while application is running
  2. Press F5 in Explorer window to refresh it
  3. Re-open Windows Explorer window
  4. If the user installed or updated ShareSync recently, try rebooting the machine

Other applications that use overlay icons on this computer may be preventing ShareSync icons from showing. Windows has a limit of 15 overlay icons on the computer, regardless of the folders.
If there are several file syncing applications installed, this limit could be exceeded, so some applications will not show their overlay icons. This is a Windows limitation so it cannot be increased.
However, you can delete or deprioritize unnecessary applications' overlays via the registry.

To do so, perform the following steps:

  1. Press the Windows key + R, type in regedit.
  2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers 
  3. Overlays in the first 15 positions are displayed.
    • To delete unnecessary applications' overlays, right-click the registry key and select Delete.
    • To deprioritize other applications' overlays, right-click the registry key, select Rename and add a Z letter at the beginning.
  4. Launch ShareSync