The files below were tested and found to be working. Each Stencils library is zipped into 2 parts. Please download both and unzip using 7zip free program that can be found here.

 
Ubiquiti Networks
 

Ubiquiti Stencil Library for Visio

The download is comprised of  2 parts. It includes all the latest Ubiquiti stencils of all the current Ubiquiti products for 2018. Download both parts and extract to open in Microsoft Visio.

 
QNAP
 

QNAP Stencils Library for visio

The download is comprised of  2 parts. It includes all the latest QNAP stencils of all the current QNAP models for 2018. Download both parts and extract to open in Microsoft Visio.