Install ca-certificates-mono by entering the following commands in the terminal:
sudo apt update sudo apt install ca-certificates-mono
Common CA certificates (Mono keystore)
Mono is a platform for running and developing applications based on the ECMA/ISO Standards. Mono is an open source effort led by Xamarin. Mono provides a complete CLR (Common Language Runtime) including compiler and runtime, which can produce and execute CIL (Common Intermediate Language) bytecode (aka assemblies), and a class library. . This package uses the hooks of the ca-certificates package to update the Mono keystore.