Referencing a library built with an older .NET version

I have a bunch of libraries and apps built in .NET 6, but I need to reference a 3rd party library that's built on 4.8. I'm getting an error, because the lib is calling System.Runtime.Remoting.Messaging.CallContext at some point, which does not exist in newer .NET versions. After countless hours of trying to find a solution, I still can't make it work. At this point, I'm basically facing the prospect of having to downgrade a bunch of my libs/apps to 4.8. Asking this question is my last ditch effort to find a more elegant solution. Thank you! :)