Archicad Layer is turned OFF ??

[Anonymous]

Hi

While working in Archicad 12, i kept on getting the pop-up message below while trying to edit various entities (many editing options are not available anymore) . I finally noticed that the Archicad layer has somehow been turned off. I can't turn it back on in the layers manager or the attribute manager (or even overwrite the layer with another AAT file). How can i get this layer back on? Note: none of the work being executed is happening on the Archicad layer.

Thanks