VSMaster Experimental instance - Cannot load Razor OOP service and attempts to create sessions stop further execution

[NTaylorMullen]

Version Used:

Steps to Reproduce:
This doesn't happen when using VSMaster proper (non-experimental instance) for whatever reason.

1. Install VSMaster build
2. git clone https://github.com/aspnet/AspNetCore-Tooling.git
3. Run ./build.cmd
4. Open src/Razor/Razor.sln
5. Run the Microsoft.VisualStudio.RazorExtension project.
6. Create a new ASP.NET Core project (can be Blazor, Razor pages, MVC, any of them).

If you want you can even git checkout 69aed0295581cf85501679f882da9d68f931ae0a to synchronize with the exact Razor bits in VS master for extra certainty (tried, fails the same way).

@ajaybhargavb tried the same repro and also ran into the same issue. This does not repro on public 16.3-preview2.

Expected Behavior:

• We can resolve information in Roslyn's OOP host

Actual Behavior:

Also, our catch never fires for whatever reason. The entire flow just stops because of how this method is exploding.

[NTaylorMullen]

/cc @heejaechang This is a huge blocker for us over at https://github.com/aspnet/AspNetCore-Tooling. Did something change in this area to break this?

FYI @rynowak @ajaybhargavb