Such error message appears when you forgot to specify the username and password in “Run As” section of the task settings. Program does not save this info to avoid credentials violation. Correct credentials should be entered each time you edit scheduled task.
You may also edit scheduled task directly in Windows Task Scheduler. To open it please run Start – Programs – Accessories – System tools – Task Scheduler or type taskschd.msc in Start and press Enter. Task will reside in Task Scheduler Library with “Paragon” task name prefix. Double click on it to edit task settings.