This plugin would be nice

Thanks for that. I would expect some way to configure that. Removing that line would also apply that to all widgets areas, on all themes, right?

My workaround is to add a plznohide class to the appropriate widget areas' divs and add this to either my theme CSS or the "Custom CSS":

.hidden.plznohide { display: initial !important; visibility: visible !important; }

It seems to work as expected. Being able to configure if each widget area should be hidden in the ACP would still be nice.

I just removed nodebb-theme-rocket and now the widgets are working. It seems like there was some kind of problem with that theme which screwed up the whole thing. Wierd.

This should do it I think.