Try selecting all of the layers and layer combinations on the right hand side - unless you want just one or two.
Barry had it:
Select the Layer combo you want to import
(upper right box) and click <<Append.
It will be added to the layer combo box on the left.
Select each Layer you want to import
(from the lower right box). Again hit <<Append
you'll see that the layers are
added to the layers box on the lower left.
Hit OK and you should get a pop-up window
warning that you are making a change.
The checkbox in AC23 eliminates the need to manually select
each layer in a selected layer combo.
Marc Corney, Architect Red Canoe Architecture, P. A.
Mac OS 10.15.7 (Catalina) Processor: 3.6 GHz 8-Core Intel Core i9 Memory: 48 GB 2667 MHz DDR4 Graphics: Radeon Pro 580X 8GB ArchiCAD 25 (5010 USA Full)