BUG #15834: Cannot install npgsql driver

The following bug has been logged on the website:

Bug reference:      15834
Logged by:          Tshepo Motsoeneng
Email address:      tshepo.motsoeneng@palota.co.za
PostgreSQL version: 11.3
Operating system:   macOS Mojave
Description:

When I attempt to install the npgsql v3.2.6-1 driver Stack Builder downloads
the file and then I get the error "Checksum verification failed for:
edb_npgsql.zip! Deleting file ...". 

Is there somewhere or another way to get this file? It's the only package
that fails to install and I suspect that it's the reason my dotnet
application is failing during DB migration.