Harass FUNC is not working with his script at my side.
For other who also have this problem add this Code under the first Loop FUNC.
bY THE wAY NICE SCRIPT 
OnLoop(function(myHero) --GOOD idea I think by MarCiii
if not IWalkConfig.Harass then return end
local unit = GetCurrentTarget()
if ValidTarget(unit, 1000) then
if Config.E then
if CanUseSpell(myHero, _E) == READY and GetCastRange(myHero, _E) then
CastTargetSpell(unit, _E)
end
end
if CanUseSpell(myHero, _Q) == READY and Config.Q then
local QPred = GetPredictionForPlayer(GetMyHeroPos(),unit,GetMoveSpeed(unit),math.huge,1000,GetCastRange(myHero, _Q),85,false,true)
if QPred.HitChance == 1 then
CastSkillShot(_Q,QPred.PredPos.x,QPred.PredPos.y,QPred.PredPos.z)
end
end
end
end)