Missing property value

[nonameolsson]

I try to use the paper-drawer-panel, but I can't get it to work. I just get this message.
paper-drawer-panel.css:31
@apply(--paper-drawer-panel-drawer-container);

Edit:
I use Ruby on Rails 4 also.

Does anyone know why I get this error?

[blasten]

It seems like Sass is complaining about @apply

[nonameolsson]

It could be that. Has anyone else tried it with Sass?

[blasten]

@addyosmani is there a way to ignore @apply in a Sass file?

[nonameolsson]

Now it works!
So I created a new rails app and installed everything in order from scratch. It worked!
After that I removed everything from the other app I tried to use before. Now it works!

I have no idea, but Sass doesn't seem complain about the @apply anymore.