I tried running a piece of code in the examples listed in Scope in https://reference.wolfram.com/language/ref/ParametricRegion.html and it gives an error.

I tried running the below code to get a conical surface:

DiscretizeRegion[
ParametricRegion[
{h Cos[\[Theta]], h Sin[\[Theta]],h},
{{\[Theta], 0, 2 \[Pi]}, {h, 0, 3}}
]]

and I get the below error:

DiscretizeRegion::drf: "DiscretizeRegion was unable to discretize the region ParametricRegion[<<2>>]

I am running Mathematica 10.4.1.0 on Windows (64-bit)

Could you please help me diagnose the issue here?