Usually, "Ohms too low" means you're trying to go too low on the resistance. Some regulated mods will not vape below a certain resistance. On my RX200S the cutoff point is .10Ω. That looks like an Alien mod to me, and my mom used to use that, but I can't quite recall the cutoff point on it. If I remember correctly, that had a .10Ω cutoff point as well, although I'm not certain on that.
If your coils are above the cutoff point, I'd say tinker with the coils a bit and/or the screws that hold your coils in place. Sometimes if the coil touches the walls of the RBA deck or they're not tightened down properly, I will get that message as well... either that or "Don't abuse protects." I've also heard that upgrading the firmware on the mod can solve this issue. Also try removing the atty, pressing the fire button to get it to say "Check atomizer" and replace the atty. This fixes a lot of issues with rebuildable coils.
Let me do a quick Google search and I can give you more suggestions.
EDIT: Apparently the 510 pin sits too deep for some tanks to make a solid connection - at least that's what I got from my Google search. You might try using a storebought coil if your RBA came with one, or maybe using a different tank. Barring that, try pulling up on the 510 pin (that's the center pin inside the top of the box where your atomizer connects - the pin on the bottom of your tank is supposed to touch the pin inside that hole. You can pull up on it with a small flat-bladed screwdriver or other similar tool.
