ASP.NET Error PRForms.dll

Hello,

After updating the Sage50 application to the 2019 version I'm receiving an error "Could not load file or assembly 'PRForms.DLL' or one of its dependencies."  when referencing Sage.Peachtree.API in an ASP.NET application.  Any Suggestions?

 I had to update my API to the .NET Framework 4.7.1

 Running on Sage 50 US Server

Release: Sage 50 Premium Accounting 2019 

Build: 26.1.00.0229 

 SDK 2019.1

Thanks