On Windows 10, 64-bit version of Notepad++. When defining a new, user defined language, clicking on any of the Styler buttons crashes Notepad++

Steps to Reproduce the Issue

1. Open Notepad++ (64-bit, latest version)
2. In menu, click on Language | Define your language
3. In "Folding in comment style" area click Styler

Expected Behavior

That the Styler would open

Actual Behavior

Notepad++ : a free (GNU) source code editor has stopped working. A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available.

Debug Information

Notepad++ v7.5.4 (64-bit)
Build time : Jan 1 2018 - 01:50:29
Path : C:\Program Files\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS : Windows 10 (64-bit)
Plugins : DSpellCheck.dll mimeTools.dll NppConverter.dll