So let’s begin here, I took some pics (not the best because im tired lol) this might make the explanation easier too.
Deck:
If you take a look at the clamp, this thing is not straight. On top it is, but going down towards the bottom it narrows down and leaves a very odd space between the posts and the clamp itself. Also since this clamp isn’t spring loaded, holding it in place while screwing down the coil, is important. If the clamp turns just slightly left or right, this will show the error later on, at least in my experience. Lets move on
Coil Height:
When installing the coil as seen here on the picture, this will cause a huge issue as well with the clamp. This coil due to the thickness of the wire will lift that clamp. Moving it down like this, is something you want to do so that you get good flavor, but again not possible if the legs are on this side. You will have to make sure, that both legs are somewhat flat in one direction, if that makes any sense. (Only reason i installed it like this is to show, that this won’t work lol)
Another important factor at least in my opinion, thick wire won’t work, the clamp is not strong enough to hold them down, no matter how hard you screw/tighten that down. I personally found, that more roundish wire will work much better than fully flat, in this rta. As well as the size.
Funny enough, I installed the coils that came with the atomizer, and got the same error message every time, either during dry burn or a couple of hits, due the the wire/legs being too thick and wide for that rta. Go figure since nobody at Vandy Vape apparently vapes, and just threw some coils in that pack without testing. Here are the pictures.
If you look at the clamp, this is what happens with their coil installed and/or coils that are made out of thicker wire, this clamp not only loosens but shifts causing that stupid error.
When cutting the ends of the coils, make sure you’re reaching inside the little grooves on the deck and cutting the legs as short as possible, not just “flush” with the deck, like you would in other rta’s. Otherwise you run the chance of shortening through the top cap.
If all this wasn’t your issue, well lets look at the last problem this rta can cause if not careful. Again I installed this on purpose like this, too show how it should not look like!
This picture will show how the wrap was pushed by the clamp right into the post. This happens very often, if a the wire is too thick, there’s too many wraps, or you didn’t squeeze your coil together while tightening that screw down.
Here’s a picture of the other side, that’s how it should look like, the leg should be straight underneath the clamp, positioned somewhat in the center.
Now i will tell you this, this rta is not meant for small coils. I vape at lower wattage too, not as low as you do, but in comparison to others around here it’s low lol. Due to the massive airflow and it doesn’t matter which one you pick, the smaller wires will have no chance on delivering any flavor since the air just flies through them, especially if you compare it with products that are made by OBS.
I took another picture to show, how your coil should fill out the deck, if you plan on getting flavor lol.
You can go bigger or smaller of course, but what I am trying to say is, if your coil is extremely spaced or only covers these airflow slits half way, you will experience very muted/washed out flavor, at least in my opinion. This is a 3.5 ID twisted SS coil, I run this in the revolver at 55-65W, not the way I normally vape but anything “smaller/thinner” is just not satisfying.
Here’s one more picture of a baby alien, I have in my hermetic RDA (works perfect in there especially with that “better” clamp), tried using this one in my revolver prior, and it didn’t do well. All I got was slightly flavored VG with a very cold vape, even closing the airflow and turning up the wattage, didn’t do anything for the flavor, because that rta is not meant for small coils like that or even smaller 
Hope you get it working, because if you do, it’s a really good RTA. If you have questions feel free too ask, just got off work and I might have forgotten a couple of things here, or made phrases that might make no sense lol.