Export Song as Audio File omits FX returns

[Gnapp]

I suddenly ran into a problem I've never seen before. When I export my Song as an Audio File, I get a dry version without the FX Returns. When I open the same project on another computer and do the export in the same manner, I get it with the FX Returns. So I guess the project file including routing is ok, but some setting in the Reason installation is off. Both my computers are running Reason 12.5d29.

Any clue?