Therefore, I am unable to properly define what might have went wrong on your end. And why the CSS file is not loaded.
Note that external CSS decoration in RadEditor is entirely based on native browser technology. Therefore, I suggest you first to investigate whether the CSS file can be loaded properly on the page.
Regards,
Ianko
Telerik
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Explore the
Telerik Feedback Portal
and vote to affect the priority of the items