Does this happen when there is no custom CSS or Javascript on the page?
What version of Skuid are you using?
Have you updated your out of date themes?

I use custom CSS. 
Millau (11.1.10) 
Not sure I understand the last question

Do you see the button here? If so, your themes are out of date. If not, you’re good to go.

Do you see this error occur after you remove all of your custom CSS off the page? In other words, is this a Skuid issue or is this a custom CSS issue. The only way to know is to check when all CSS has been removed