System method stopped working?

Question

.NET

I wrote a program that, through process, launches the command to change the power scheme. Worked great for a whole year. Recently, the power scheme simply does not change; The program responds to button presses, but does not perform any actions.
The program also has a built-in Win API function that displays the processor load. It also just stopped working, does not display anything.
Didn't update anything, didn't change anything, didn't rebuild anything. What is this witchcraft, and how to fix it?

Answer 1

Apparently not enough rights.