This is my home desktop PC, I am the only person that uses this computer, my account is (supposed to be) the administrator account and I am logged in with my Microsoft account, there are no other user accounts. -- As stated above, I am trying to create a simple, basic scheduled task like I did many times in Windows 7 with no issues whatsoever, but now that I have upgraded to Windows 10 (current version: 1511) I am experiencing "An error has occurred for task - Error message: The specified account name is not valid" when trying to save the new task. I have been for days trying to find a fix online, but either I'm blind or stupid as everything I have tried fails with the same error (see attached snip).
I don't seem to be having any other "account name is not valid" issues with any other programs, and this is the first time I have ever seen this particular problem in all of the years I have used Windows.
Any help/suggestions would be very much appreciated, and thanks ahead of time.