You will receive this error if an instance of Sync & Save is already running under a different user account.

In order to run Sync & Save under the current logged in user, you will need to close the existing instance of Sync & Save:

• Open Task Manager (type "Task Manager" in the search box of the Start menu).
  
  
• Click "Show processes from all users."
  
  
• Switch to the Processes tab and find the SyncAndSave.exe process.
  
  
• If the User Name listed next to the SyncAndSave.exe process is different than the current user then there are two options:
  1. Switch users to the listed user and close Sync & Save normally (preferred).
  2. End the process by selecting the process and clicking End Process.
  
  
• If the User Name listed next to the SyncAndSave.exe process is the same as the currently logged in user there is only one option:
  1. End the process by selecting the process and clicking End Process.
  
  

Sync & Save is not designed as a multi-user application. The files that store job configuration are shared between all sessions/instances so if two users (the task scheduler should be thought of as a user) were to edit the configuration of the same job at the same time, the last user to save the job would overwrite the changes made by the previous user.