OMBG (Bill Gates) You need to read and get security policy and the respect it has to place on a hierarchy of upstream objects and credentials. Well that's the MS answer and attitude...
The reality is if you are working with server OSs you need to understand their security & policy frameworks, and how to debug them :). If your process loses the necessary file permissions or rights (2 different things) you should ask: "Hot damn, why didn't I fix that in the config/setup". People that blast the vendor/project (or even @#@#&$! MS) are just blinding themselves to the solution/s.
In most cases this kind of issue is due to Windows' AD removing the rights of a Local administrator User to run a scheduled task. It is a common security setting in corporate networks (implemented with glee by Domain Admins to upset developers) though it is really a default setting these days. It happens because the machine updates against an upstream policy (after you've scheduled a task) and decides that all of a sudden it won't trust you to run it (even though previously it let you set it up). In a perfect world it wouldn't let you set it up in the first place, but that isn't the way policy applies in Windows... (@#@#&$! MS). LOL
Wow it only took 5 months to get an answer! (but here they are for the next person at least!)