Double-clicking a JSON file to try and open it in Visual Studio 2017 Professional doesn’t work; VS2015 worked fine. This link explains how to fix for the Community edition. The same principle applies for VS2017.
Using regedt32 first find the Visual Studio magic number:
Key: Computer\HKEY_CLASSES_ROOT\.json\OpenWithProgids Value: VisualStudio.json.a8eb385c
Then find the associated shell key and create a new sub-key ‘Command’ with the path to devenv.exe as the default value:
Key: Computer\HKEY_CLASSES_ROOT\VisualStudio.json.a8eb385c\shell\Open\Command Value: "C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE\devenv.exe"
Right-clicking a JSON file and selected Open with now looks like this:
Carpe Diem Systems Ltd. 