selectize.js:2151 Uncaught TypeError: Failed to execute 'appendChild' on 'Node': parameter 1 is not of type 'Node'

[epchristi]

In selectize.js, in the function refreshOptions(), optgroup can be IPV6ADDRESS, and in line 2151:

html_children.appendChild(self.render('optgroup_header', self.optgroups[optgroup]));

This call fails with the Uncaught TypeError. 'optgroup_header' doesn't have a mapping in self.render.

This may or may not be a problem, but html[0] ends up being undefined in this case, which is what results in the error. I would add the code that causes it, but it's proprietary. I am hoping this gives enough information to reproduce it in a different way.