Object.extname is deprecated.

[golf-chanagun]

Argument to path.extname must be a string

Object.extname (C:\Users\golf_chanagun\AppData\Local\atom\app-1.13.0-beta4\resources\app.asar\src\electron-shims.js:20:10)
AtomReact.autoSetGrammar (C:\Users\golf_chanagun\.atom\packages\react\lib\atom-react.coffee:162:22)
AtomReact.processEditor (C:\Users\golf_chanagun\.atom\packages\react\lib\atom-react.coffee:361:12)
<unknown> (C:\Users\golf_chanagun\AppData\Local\atom\app-1.13.0-beta4\resources\app.asar\src\workspace.js:334:16)
Function.module.exports.Emitter.simpleDispatch (C:\Users\golf_chanagun\AppData\Local\atom\app-1.13.0-beta4\resources\app.asar\node_modules\event-kit\lib\emitter.js:25:14)
Emitter.emit (C:\Users\golf_chanagun\AppData\Local\atom\app-1.13.0-beta4\resources\app.asar\node_modules\event-kit\lib\emitter.js:129:28)

[PaulAndreRada]

Just update, It will solve it. in Atom, click on the deprecated alert on the bottom of your window, you'll see the update button on top.