JavaScript not working

I have unity free and javascript isnt working on it for some reason i use c# mostly but java is what i see most scripts as and it wont open any JS script and i cant alter any that i make.

this is the error that comes up or atleast part of it.

The file ‘H:\Animation\Unity\Test\Assets\OtherScript\hola.js’ could not be opened. The type initializer for ‘Boo.Lang.Compiler.TypeSystem.Types’ threw an exception.

You may need to install .net framework version 4.5.

Here is the download link:

Got this info from: I can't open boo or js scripts in Monodevelop with a default install? - Unity Answers