It is a problem ... the template that comes with the door is pretty flimsy and if you lose that, you're out of luck unless pretty clever and good at measurements. Even the "door installation" instructions at Larson's web site don't include the template; not very nice of them! I guess they want only "qualified" people installing their doors. And, with Lowes, their people are nearly worthless at giving tips, even if you can find one! And, a lot of the products are on "special order," which means a long wait and additional costs.
Good luck with your search.
