Hi,

Sorry, I could not reproduce the problem, here is the exact same example as yours: https://codepen.io/svetoslavjqwidgets/pen/GRYEYEN
You may see that an error is not received.
May please check your version of Smart UI, you can also send us a demo with the problem.

We are waiting for you!

Best Regards,
Svetoslav Borislavov

Smart UI Team
https://www.htmlelements.com/