Getting whether there's a valid path between entity and point?

[Zet0r]

Using navmeshes, would it be possible to get whether there'd be a valid path between any given entity (even non-nextbots) and position? The plan is to use this to determine whether a spawnpoint for the nextbots would be valid or not by using the spawnpoint entity as the start so that the bots only spawn where they can get to players. I have already tried fiddling with it by using path:Compute() and a custom function, but it keeps returning failed and doesn't print the messages inside the function.
[lua]function HasValidPath(start, target)
print("Beginning")
local path = Path("Chase")
path:SetMinLookAheadDistance( 300 )
path:SetGoalTolerance( 50 )
print(path)

//Compute a path - return true if it exists
path:Compute( start, target, function( area, fromArea, ladder, elevator, length )
print("Computing ...")
if ( !IsValid( fromArea ) ) then
print("In same area")
return true
else
if ( !startent.loco:IsAreaTraversable( area ) ) then
//Our locomotor says we can't move here
print("Not right")
return false
end

//Check height change
local deltaZ = fromArea:ComputeAdjacentConnectionHeightChange( area )
if ( deltaZ >= self.loco:GetStepHeight() ) then
if ( deltaZ >= self.loco:GetMaxJumpHeight() ) then
//Too high to reach
print("Too high")
return false
end
end
print("Possible!")
return true
end
end)

print(path)
return path:IsValid()
end[/lua]
The pathfinding function used here is the same as the one used on the nextbots spawning, except just returning true or false and not calculating the cost. I have tried returning -1 and 0 instead but both times path:IsValid() is false. Would this type of thing be possible without the use of a nextbot?