Adding references

For now there are only one way to edit them - editing *.csproj file. Sorry for any inconveniences. You're welcome to vote here https://youtrack.jetbrains.com/issue/RIDER-409

Kirill Falk 

Also sorry if this is obvious but I'm new in Rider. How can I add a reference to a netstandard2.0 library (from a separate project) into a .netcore solution. I have tried:

netcore add[<PROJECT>] reference <PROJECT_REFERENCES> which adds the reference in csproj file but I see the error (has missing packages) next to my project node in the Solution Explorer.

I'm working on a Mac

I've got the same issue as Luis. Adding a reference to a local project breaks NuGet-references. 

In fact, my project shows it can't find any System-packages (System.Collections.Generic & System.Test.RegularExpressions to be specific) as well as Microsoft-packages, even though they were previously referenced. When I then try to install the missing Microsoft-packages, it gives me an error message 'Install failed (project: X, package: "Microsoft.AspNetCore.Mvc.Core v2.2.0) Package restore failed. Rolling back package changes for 'X''.

Looking through the log it appears that the root of many of the installation-issues I'm having and the source of these error messages is the fact that the ASP.NET Core Web Application-template doesn't yet support NetCoreApp2.2 and with it packages like AspNetCore.Http.Extensions 2.2.0. I referenced a project that did use one of these incompatible packages, which broke all of the references. 

I fixed it by downgrading the NuGet-packages from this other project to a supported version (specifically 2.1.1).