Recent update broke my top navigation bar

[tophee (Christoph)]

OK, I believe I fixed it. The disappearing header was not related to my fix but caused by this theme component:

IFrame Lightboxes

This is a theme component that adds the ability to open iFrames in lightboxes. Samples This component adds an “expand” button on top of the iframes you enable it on. [expand button] Clicking the button will open the iframe in fullscreen in a lightbox. [full screen iframe lightbox] Clicking either the dark area around the iframe or the x at the top right corner closes the lightbox. The same way it works for default image lightboxes. Settings There’s only one setting. You add the domains…

Removing it made solved the problem. Perhaps @Johani understands what is causing this? Perhaps it is related to the

Additional control of iframes in oneboxes

introduced in Discourse Version 2.6 - #2 by neil?