Only 3 sidebars work

Hi there,

I recently updated the pinboard theme (after ~1 year). Everything is alright except that one of my widgets is gone. I’ve been trying for hours to add a widget called revolution slider to the wide sidebar, but it seems that only 3 of the sidebars work: the header, footer and footer wide. These 3 are also the only options which show up when I try to add widgets through the customizer. I see all 10 of the sidebars at the widget tab, and it is possible to add widgets to them. But that will result in nothing.

Is this a bug? Or a fault on my part?

Thanks in advance