koobas.hobune.stream
"Error Invalid option '6' for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default" using .Net 4.6
I'm trying to use the new experimental version of .net 4.6, but I keep getting the error "Error Invalid option '6' for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default" and I don't how to fix it, when reverted to .net 3.5 that error is gone but I get a bunch more because I've got code that depends on .net 4.6.
The error doesn't show a line and when I double click on it, I get the message "File not Found C:Users\Username\Documents\Projectname\CSC", but it says the error originates from the file "CSC".
I thought the C# compiler was downloaded when you installed unity, and it works with .net 3.5 so I don't know what to do to resolve the error.
(I'm using Unity 2017.1.0f3)
Do this steps https://stackoverflow.com/questions/32070490/how-to-build-net-4-6-framework-app-without-visual-studio-installed
After if You have a Rider IDE go to File -> Settings -> Build -> and check the auto detected Image for more details below 
Don't forget update Rider to 2017.3.1 version or higher and reinstall plugin JetBrains inside your Plugins folder
After this steps You can build your projects on .Net 4.6
Hope it was helpful
