Users may experience an error stating "Authentication with the ShadowLink Service failed: Unable to connect to the remote server" as per the image below:

Upon further research in the event viewer they may also see an error "Faulting application name: ShadowLink.Client.exe  Faulting module name: KERNELBASE.dll"..."Faulting module path: C:\Windows\system32\KERNELBASE.dll"  as seen in the image below:

If their event viewer shows the error noting KERNELBASE.dll, their machine is having issues with a critical system file used across numerous applications.  This error can unfortunately mean a number of things.

The easiest resolution found is to do a system restore to a time in which the service was operating normally.  Users should understand what a system restore will do for their machine, they may find more information at these links:

Windows 7 - http://windows.microsoft.com/en-us/windows/what-is-system-restore#1TC=windows-7
Windows 8 - https://support.microsoft.com/en-us/help/17085/windows-8-restore-refresh-reset-pc
Windows 10 - https://support.microsoft.com/en-us/help/12415/windows-10-recovery-options