Type of expression is ambiguous without more context

I get this error while compiling

`/Frameless/Frameless/AppDelegate.swift:83:55: Type of expression is ambiguous without more context`

on

```
macbookproloreto:$ xcodebuild -version
Xcode 7.3.1
Build version 7D1014

$ sw_vers 
ProductName:    Mac OS X
ProductVersion: 10.11.6
BuildVersion:   15G31
```
