Oh, interesting. Though we do have a "not enough energy" error, it just doesn't always display when you'd expect it to.
What I reported may be a subtly different problem, though. It seems that you get a "not enough time units" error when failing an "open door" click, regardless of why it didn't work. Last night I was on a TFTD or TFTD-inspired terror map whose doors apparently don't close once opened. (You can walk straight through them once open, and they don't budge.) I didn't realize that at first, though, and got the "not enough time units" error when trying to click one shut, with both TU and Energy to spare.