Uncaught TypeError: Cannot read property 'className' of undefined

[rig1]

I created a project using Ionic Materail. I am getting a error when one of my html is getting called.
The error is
Uncaught TypeError: Cannot read property 'className' of undefined, http://localhost:8100/lib/ionic-material/dist/ionic.material.min.js, Line: 13
I have added ionic.material.min.js in the index.html. I don't understand what's wrong?
Any help will be greatly Appreciated.

[kashban]

See this issue: #43

There I explain where the error stems from and how to get around it.

Also this is a duplicate of #161