Edit and Continue Not Supported for F#
For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.
Edit and Continue is not supported when you debug F# code. Edits to F# code are possible during a debugging session but should be avoided. Code changes are not applied during the debugging session. Therefore, any edits made to F# code while you debug will result in source code that does not match the code being debugged.