Sorry for the ress, but I solve this in Persona with HTML and CSS, just declarating the Sidebar widget-area in categories.tpl and CSS to fix the categories width.
I'm newbie with front-end, but this "fix" is functional atm.

Thanks, we have it working now!

@psychobunny have good holidays

GH : https://github.com/NodeBB/NodeBB/issues/3743

panpansh created this issue in NodeBB/NodeBB closed Creating widget area work for ACP but not present in forum html #3743

@baris Guess that should have been the obvious, and yeah, we had some code that would auto generate a background for users. Disabling that did fix it. I really appreciate the help, feel kind of stupid now lol. Besides that being fixed now we still have an ongoing issue with plugins not working like emoji's, shoutbox, and so on. And words of advice on that?

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.

Answer to self: enable the custom header and the global vars will be there. Sounds about right?