Description of the Issue

When using the Create New or Save As.. buttons in the user defined language dialog, the program crashes

Steps to Reproduce the Issue

1. Open Notepad++ and select Language->Define your Language...
2. Click either the Create New... or Save As... buttons
3. Enter any name and press ok.
4. Notepad++ crashes.

Expected Behavior

I expected it to add a blank user language that I could then edit.

Actual Behavior

Notepad++ crashes

Debug Information

Notepad++ v7 (64-bit)
Build time : Sep 21 2016 - 22:07:28
Path : C:\Program Files\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS : Windows 10
Plugins : mimeTools.dll NppConverter.dll