Pyssel

ViewSonic SC-T25, VS,  handles certificates , cert, for different applications in  Base64-encoded DER format . If You open the certificate file, with a simple text editor, it shall begin with  "---- BEGIN CERTIFICATE ----" and end with  "---- END CERTIFICATE ----" if it is the right format. The most simple way to load the cert, is to use "Method 1" . Please note that You log in with the  CLIENT , PC/Mac, user/password. Another method is "Method 3" . In this example I will load Citrix Intermediate Certs to the  SC-T25 from a USB stick.

This cost effective Thin Client is based on Raspberry Pi 3 and together with Stratodesk OS it is very versatile If You bought, or got, the thin ViewSonic client, VT, produced before date 2017-07, You can upgrade to the better Stratodesk NoTouch OS with out any cost. This OS  is the "standard" OS for new devices.