Built-in CSS editor seems to have failed: Blank window when Appearance - Customise selected


I’m using Sydney Pro version 2.0.13.

When I select “Customise” from the “Appearance” menu, all I get is a blank page.

Where have all the customisation options gone?

The same thing happens when I click Appearance - Header\Background.

Thanks in advance,



Can you please provide a link to your website?

Kind Regards, Roman.
aThemes Support