Simply targeting anything (hostile or not) with v8.3.0.00 results in this error:

Message: Interface\AddOns\HeroRotation_DemonHunter\Havoc.lua:255: attempt to compare number with boolean
Time: Sun Mar 8 11:23:13 2020
Count: 206
Stack: Interface\AddOns\HeroRotation_DemonHunter\Havoc.lua:255: attempt to compare number with boolean
[string "=[C]"]: ?
[string "@interface\AddOns\HeroRotation_DemonHunter\Havoc.lua"]:255: in function Cooldown' [string "@Interface\AddOns\HeroRotation_DemonHunter\Havoc.lua"]:462: in function ?'
[string "@interface\AddOns\HeroRotation\Main.lua"]:439: in function <Interface\AddOns\HeroRotation\Main.lua:417>

Locals:

This has been fixed in commit ae59b49

Thanks for the report!