Win8.1 OneDrive sync error - UAC nag?

Today when I start my computer, this error comes up (translated, not exact message);

Cannot activate this app when UAC is deactivated.

I haven't made any changes, and have no clue why this suddenly happened.

Any suggestions?

It's sorted itself out. All of a sudden the error disappeared. Weird... :-/

And all of a sudden the error is back. Obviously something happend. Any ideas?