VS2019 crashes when an F# source contains this string: let xxx x y = (# "divvvv" x y : float #) #7164

My installation of Visual Studio 2019 (version 16.1.5) crashed after I typed in this code and refuses to open the project again:

let xxx x y = (# "divvvv" x y : float #)

Repro steps

1. Open an F# project in VS2019
2. Type in the above code
3. Mouse over the code.

Expected behavior

It should probably show an error that reads "Don't mess with stuff you don't understand, kid."

Actual behavior

Crashes completely.

Known workarounds

Open the file in another editor, remove that code.

• Operating system Windows 10
• .NET Runtime kind dotnet core 3.0 preview 6
• Editing Tools VS 2019