I'm trying to use the recently-released .NET 7 RC1 with Visual Studio 17.4 Preview 2. Unfortunately, I'm unable to build my project because it uses ANTLR at one point, and the ANTLR extension for Visual Studio didn't get installed.
I have the VSIX file, but when I run it, it says:
When I open the Manage Extensions window, there doesn't appear to be any option anywhere to load an extension from disc.
What is the mechanism for getting this extension installed into a Preview version of VS?