Closing preference window manually and later trying to close it with the appropriate button causes an error

[blahsd]

Could not call remote function 'close'. Check that the function signature is correct. Underlying error: Object has been destroyed
Error: Could not call remote function 'close'. Check that the function signature is correct. Underlying error: Object has been destroyed
    at callFunction (/Users/.../dev/proj/snwe/node_modules/electron-prebuilt/dist/Electron.app/Contents/Resources/electron.asar/browser/rpc-server.js:235:11)
    at EventEmitter.<anonymous> (/Users/.../dev/proj/snwe/node_modules/electron-prebuilt/dist/Electron.app/Contents/Resources/electron.asar/browser/rpc-server.js:342:5)
    at emitMany (events.js:127:13)
    at EventEmitter.emit (events.js:201:7)
    at WebContents.<anonymous> (/Users/.../dev/proj/snwe/node_modules/electron-prebuilt/dist/Electron.app/Contents/Resources/electron.asar/browser/api/web-contents.js:231:13)
    at emitTwo (events.js:106:13)
    at WebContents.emit (events.js:191:7)

[blahsd]

This was fixed at some point