hi , i have downloaded your added project and run it in my system,
it is showing same error, please check the attached video
https://drive.google.com/file/d/1zM_Q1EVdDD7V0aa8FCyunx3eobNChXY0/view?usp=sharing
so detail of xamarin form version and sfpdfviewer nuget version is mentioned in your project
and i am sharing details of my emulator